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Showing papers on "Balun published in 2014"


Journal ArticleDOI
TL;DR: In this paper, the authors demonstrate direct quadrature modulator and demodulator monolithic microwave integrated circuits for future terahertz communications at 300 GHz based on the Quadrature Phase-Shift keying (QPSK) modulation format.
Abstract: We demonstrate direct quadrature modulator and demodulator monolithic microwave integrated circuits for future terahertz communications at 300 GHz based on the quadrature phase-shift keying (QPSK) modulation format. For the modulating and demodulating signal, we employed half-Gilbert cell mixers, which provide balanced signaling and moderate performance in conversion efficiency with a simple circuit configuration. In order to maintain the balance performance of the modulator and demodulator, passive baluns and couplers are implemented with thin-film microstrip lines, which exhibit less insertion loss than inverted microstrip lines (IMSLs), while the active mixers are based on IMSLs for short interconnections. The half-Gilbert-cell mixers have a wide enough operation bandwidth for high-throughput communications of more than 10% at 300 GHz. According to the static constellation of the modulator, imbalance is expected to be less than approximately ±0.6 dB ∠4°. A nonchip back-to-back experiment was conducted at up to 60 Gb/s, and 50-Gb/s operation was verified with a low bit error rate on the order of 10-8 or less. The results demonstrate that the QPSK modulation scheme can be applied to double the data rate at terahertz frequencies.

110 citations


Journal ArticleDOI
TL;DR: In this paper, a dual-polarized patch antenna with low profile and wide bandwidth is presented, where the square patch, where a bow-tie slot is etched on, is excited by two different balance-to-unbalance feedings for dual polarization.
Abstract: In this letter, a dual-polarized patch antenna with low profile and wide bandwidth is presented. The square patch, where a bow-tie slot is etched on, is excited by two different balance-to-unbalance feedings for dual polarization. One of the polarizations is excited by the central-placed transition, which transfers the unbalanced microstripline feed to the balanced slot feed. The other polarization is excited by a differential feed network, which contains two capacitively coupled probe feeds. By adopting the two balanced feedings, high isolation and low cross polarization are achieved. A prototype of the proposed antenna is built and tested. Measured results show that the $ - $ 10-dB reflection coefficient bandwidth of the two polarizations is about 18.8%, with port isolation less than $ - $ 28.5 dB.

63 citations


Journal ArticleDOI
TL;DR: The demonstrated cancellation system subtracts the in-band wideband interfering signal from the received signal, such that the weak signal of interest (SOI) can be recovered, the first demonstration of such a wide bandwidth cancellation with good cancellation depth.
Abstract: A wideband co-site co-channel interference cancellation system (ICS), based on hybrid electrical and optical techniques, is proposed and is experimentally demonstrated. The demonstrated cancellation system subtracts the in-band wideband interfering signal from the received signal, such that the weak signal of interest (SOI) can be recovered. Our system utilizes a broadband radio frequency (RF) Balun transformer to invert the phase of the interfering signal, while electro-absorption modulated lasers are used for converting the RF signals into the optical domain to enable fine adjustment with the hybrid ICS. We experimentally achieve 45 dB of cancellation over a 220 MHz bandwidth, and over 57 dB of cancellation for a 10 MHz bandwidth, at a center frequency of 900 MHz. The proposed system also experimentally shows good cancellation (30 dB) over an enormously wide bandwidth of 5.5 GHz. To the best of our knowledge, this is the first demonstration of such a wide bandwidth cancellation with good cancellation depth. This property is extremely useful when there are multiple interference signals at various frequency bands. The proposed hybrid ICS has a spurious-free dynamic range of 93.2 dBm/Hz(2/3). Moreover, a 10 Gb/s SOI is recovered from a strong interfering signal, sweeping over 3 GHz bandwidth. A widely open eye diagram, as well as error-free bit-error rate measurements, is experimentally achieved, with the use of the hybrid ICS. The approach also works well for various frequency bands that are within the bandwidth of the Balun transformer and electro-absorption modulated lasers.

61 citations


Journal ArticleDOI
TL;DR: In this paper, a dual-band balun bandpass filter (BPF) with high selectivity is proposed and implemented by taking advantage of the existence of multiple substrate integrated waveguide (SIW) cavity modes.
Abstract: A new method of designing a dual-band balun bandpass filter (BPF) with high selectivity is proposed and implemented by taking advantage of the existence of multiple substrate integrated waveguide (SIW) cavity modes. The major design concept applied in this letter is based on two mechanisms: one is by properly placing the output ports to achieve the balanced output for both passbands, and the other is by taking cross coupling of higher/lower order modes to achieve transmission zeros (TZs) at each side of the passband. Two internal coupling slots are involved to separately control the coupling level between cascaded cavities for each passband. A prototype operating at $9.0~{\rm GHz}$ and $9.8~{\rm GHz}$ has been realized and shows the desired filtering performance. The differences between the two outputs are within $180^{\circ}\pm 2^{\circ}$ in phase and $0.6~{\rm dB}$ in magnitude across the two passbands. Measured frequency responses agree well with the simulated ones in this work.

55 citations


Proceedings ArticleDOI
01 Jun 2014
TL;DR: In this paper, vertically integrated inkjet-printed inductors and transformers are demonstrated for the first time with high levels of performance and repeatability using a well-characterized multi-layer inkjet printing process which is substrate independent and optimized for the fabrication of RF components.
Abstract: Vertically-integrated inkjet-printed inductors and transformers are demonstrated for the first time with high levels of performance and repeatability. The inductive components are fabricated using a well-characterized multi-layer inkjet printing process which is substrate independent and has been optimized for the fabrication of RF components. Printed spiral inductors with values of 10 nH and 25 nH are demonstrated with a maximum Q of over 20 at 1 GHz, which is the highest Q value reported to date for printed components, and a repeatability of within 5% between fabrication runs. Printed inductively coupled transformer-based baluns are also demonstrated which operate at 1.4 GHz with a maximum available gain of -1.7 dB.

51 citations


Journal ArticleDOI
TL;DR: In this article, the transversal signal-interaction concepts have been extended to the design of differential wideband/UWB balanced bandpass filters with broadband common-mode suppression in their former works.
Abstract: This article presents an introduction of recently wideband bandpass filters based on transversal signal interaction concepts. Different resonant structures are reported on, including branch-line coupler/ring resonator, interdigital coupled lines, DSPSL 180° phase-shifting structure, Marchand balun, open/shorted coupled lines, T-shaped structures, and open/shorted stubs. Detailed comparisons of out-of-band transmission zeros, effective circuit size, 3-dB bandwidth, upper stopband, and group delay for the wideband/UWB filters discussed in this article are presented. Different bandwidth of wideband bandpass filters can be realized based on transversal signal interaction concepts, branch-line coupler/ring resonator can be easy to realize wide bandwidth with narrow upper stopbands due to their harmonic response. The filter structures using different 180° phase-shifting structures such as DSPSL, shorted coupled lines, and Marchand balun can meet UWB bandwidth/band demand, and the circuit size can be further reduced, while the selectivity and upper stopband should be further improved. The integrated applications of shorted/open coupled lines and shorted/open stubs can increase the numbers of the transmission zeros out-of-band, besides the circuit size reduction, the upper stopband can be also extended to over 4.7 f0 . Moreover, the transversal signal-interaction concepts have been also extended to the design of differential wideband//UWB balanced bandpass filters with broadband common-mode suppression in our former works.

50 citations


Journal ArticleDOI
TL;DR: A new millimeter-wave power-combining technique using transmission-line baluns which both connect transistor outputs in series and inductively tune the transistor output capacitances is presented.
Abstract: We present a new millimeter-wave power-combining technique using transmission-line baluns which both connect transistor outputs in series and inductively tune the transistor output capacitances. The baluns are much shorter than a quarter-wavelength (λ/4), hence are more compact and have less insertion loss than a λ/4 balun. We introduce one topology providing an even number of series connections, including 2:1 and 4:1, and a second topology providing either an even or odd number of series connections. We then analyze segmented transformer power-combiners as a set of multi-conductor transmission-lines, and explore the relationship between transformer and transmission-line balun power-combiners. We demonstrate the technique with 2:1 and 4:1 series-connected designs implemented in a 0.25 μm InP HBT process. At 86 GHz, a single-stage power amplifier (PA) using the 2:1 baluns exhibits 30.4% peak PAE, 20.37 dBm output power (Pout) and 23 GHz 3-dB bandwidth from a 448 × 816 μm 2 die. A two-stage PA using the 2:1 baluns exhibits 30.2% PAE, and 23.14 dBm Pout from an 824 × 816 μm 2 die. At 81 GHz, a two-stage PA with 4:1 series output power-combining exhibits 23.4% PAE, and 26.7 dBm (470 mW) Pout from a 1,080 × 980 μm 2 die.

46 citations


Journal ArticleDOI
TL;DR: In this paper, a probe-fed stacked annular patch antenna is proposed for Global Navigation Satellite System (GNSS) applications, which is designed to operate at the satellite navigation frequency bands including GPS, GLONASS, BDS-1, and BDS-2.
Abstract: A novel probe-fed stacked annular patch antenna is proposed for Global Navigation Satellite System (GNSS) applications. The antenna has been designed to operate at the satellite navigation frequency bands including GPS, GLONASS, BDS-1, and BDS-2. In the design, four annular patches are stacked to achieve multiband operation and compactness. Quadrature phase feed network comprising four 90° stripline baluns is employed to ensure circularly polarized (CP) radiation. Another key feature of our design is the stepped-radius shorting pillar to reduce the well-known inductance due to longer feeding probes. The final antenna exhibits good impedance matching, broad pattern coverage, and pure CP performance at all designed bands. Details of design considerations and experimental results are presented and discussed.

44 citations


Proceedings ArticleDOI
24 Mar 2014
TL;DR: A balanced-to-single-ended (BTSE) power divider that provides all the desired performances within the operating bandwidth of 25%, with low insertion loss and good balance also achieved.
Abstract: A balanced-to-single-ended (BTSE) power divider is proposed in this paper. Its input is a differential pair while both the outputs are single-ended ports. It can replace the cascade of a balun and a conventional power divider. The characteristics requirements of a two-way BTSE power divider with equal power division are first derived, and then a prototype is designed for 2.0 GHz. In order to construct the component compactly, a short-ended four-wire coupled line and T-shaped sections are utilized to realize a -90° transmission line and a phase inverter, respectively. The developed prototype occupies an area of 0.077 λ g 2 , where λ g is the guided wavelength of central frequency. It provides all the desired performances within the operating bandwidth of 25%, with low insertion loss and good balance also achieved.

42 citations


Journal ArticleDOI
TL;DR: In this article, an enhanced double-balanced Gilbert cell with current injection was used to reduce power consumption, and dual negative resistance compensation (NRC) was also used to improve conversion gain.
Abstract: We report a 79 GHz mixer for direct up-conversion using 90 nm CMOS technology. In the mixer, an enhanced double-balanced Gilbert cell with current injection is used to reduce power consumption, and dual negative resistance compensation (NRC) is used to improve conversion gain (CG). In addition, it also includes two Marchand baluns: the single LO input signal to differential signal is converted by one of the baluns, and the differential RF output signal to single signal is converted by the other. The mixer consumes 13.6 mW, achieving IF-port input reflection coefficient (S11) of - 11.4 dB at 0.1 GHz, LO-port input reflection coefficient (S22) of - 12.2 ~ - 28.7 dB for frequencies 75-90 GHz. At IF of 0.1 GHz and RF of 78.1 GHz, the mixer achieves CG of 2.1 dB and LO-RF isolation of 35.9 dB, the best CG and isolation results ever reported for a W-band silicon-based mixer with power consumption lower than 15 mW.

35 citations


Journal ArticleDOI
TL;DR: In this article, a printed compensated balun of simple structure for enhanced ultra-wideband performances is presented, which stems from the generic compensated type of Marchand balun with an optimization on selected parameters for the bandwidth enhancement.
Abstract: This letter presents a printed compensated balun of simple structure for enhanced ultra-wideband performances. The presented design stems from the generic compensated type of Marchand balun with an optimization on selected parameters for the bandwidth enhancement. A simple planar structure based on a 3-metal-layered PCB is proposed to realize the optimal design of the circuit scheme. The proposed balun design was implemented on a standard FR4 PCB and successfully verified with consistent simulation and measurement results. The presented balun achieves ultra wideband performances with a return loss better than 10 dB from 0.45 GHz to 6.85 GHz, a bandwidth ratio of 15:1. Over the entire bandwidth, the magnitude and phase imbalances are within 0.5 dB and 10 °, respectively. To the best of our knowledge, this work performs the largest bandwidth among the printed or planar baluns reported in the literature to date.

Journal ArticleDOI
TL;DR: In this article, a series-fed two-dipole antenna, fabricated on a liquid crystal polymer (LCP) substrate using inkjet-printing technology, was studied using the microstrip line.
Abstract: This paper presents a series-fed two-dipole antenna, fabricated on a liquid crystal polymer (LCP) substrate using inkjet-printing technology. The radio frequency characteristics of inkjet-printing silver film onto an LCP substrate are studied using the microstrip line. The proposed antenna consists of two modified dipole elements of distinct lengths: a modified ground plane and a balun filter yielding a wide bandwidth with bandpass responses. The proposed antenna can be used at frequency band of 26-33 GHz. The bending behaviors of the microstrip line and antenna are also measured. Inkjet printing on LCP substrates provides a low-cost, compact, and flexible packaging solution that can be used in future communication technology.

Journal ArticleDOI
TL;DR: In this paper, a triple-push oscillator with differential output was proposed, which can provide differential output without any additional active circuit or passive balun required, therefore, the output power can be increased and the chip area and power consumption can be reduced.
Abstract: A low-power triple-push oscillator with differential output is proposed in this letter. By extracting signals from the same current loop, the oscillator can naturally provide differential output without any additional active circuit or passive balun required. Therefore, the output power can be increased and the chip area and power consumption can be reduced. Realized in 40 nm CMOS technology, the proposed oscillator can oscillate at 340.6 GHz while providing equivalent isotropically radiated power (EIRP) as -21.8 dBm. The power consumption is only 34.1 mW from a 0.9 V supply. The oscillator core only occupies area of 0.028 mm 2 .

Patent
15 Oct 2014
TL;DR: In this article, a low-profile broadband dual-polarized omni-directional antenna is proposed. But the antenna is not suitable for low-power applications, as it requires a large number of antennas to be arranged side by side.
Abstract: The invention discloses a low-profile broadband dual polarization omni-directional antenna. The antenna comprises a vertical polarization monopole antenna and a horizontal polarization loop antenna which are arranged side by side, and the loop antenna is composed of four rotational symmetric arc-shaped dipoles. A metal cylinder wraps a monopole feed probe to increase the monopole bandwidth, and parasitic units and directors are loaded outside dipole arms to increase impedance bandwidth of the loop antenna and gain out-of-roundness of the loop antenna on azimuth planes is reduced. The low-profile broadband dual polarization omni-directional antenna basically comprises an upper medium plate (1), a lower medium plate (2), plastic screws (3), a round patch (4), a loop patch (5), the feed probe (6), the metal cylinder (7), a metal floor (8), metal short circuit columns (9), arc-shaped printed dipoles (10), L-shaped feed baluns (11), the parasitic units (12), the directors (13), a coaxial line (14), 100 ohm microstrip lines (15) and a small metal wafer (16).

Journal ArticleDOI
TL;DR: In this paper, a new design methodology is presented for the planar implementation of a classical Marchand balun, which can be designed optimally to eliminate the phenomenon of trace separation, which is frequently observed in planar implementations.
Abstract: A new design methodology is presented for the planar implementation of a classical Marchand balun. A novel intuitive analysis shows that the Marchand configuration can be designed optimally to eliminate the phenomenon of “trace separation,” which is frequently observed in planar implementations. The new theory shows that this unbalancing effect is caused by the parasitic transmission line formed between the inner strip and ground, which is not considered in Marchand's original coaxial structures. Compact design equations are derived, based on which a new innovative structure is proposed and fabricated. This demonstrates the elimination of trace separation and achieves flat equal port split over a double octave bandwidth, performing up to 10 GHz, using an industry standard single-layer thin-film process having a continuous unpatterned ground plane. Popular planar variants of Marchand's original structures are also designed and fabricated to verify the new design equations. These structures are compared in terms of bandwidth, trace separation, and balanced port impedances.

Journal ArticleDOI
TL;DR: A series-fed two-dipole antenna fabricated on a flexible liquid crystal polymer (LCP) substrate by using inkjet printing technology was presented in this paper, where the bending effect of the antenna was considered when calculating the gain loss and bandwidth reduction.
Abstract: This letter presents a series-fed two-dipole antenna fabricated on a flexible liquid crystal polymer (LCP) substrate by using inkjet printing technology. The proposed antenna consists of two modified dipole elements of distinct lengths, a director element, a modified ground plane, and a balun filter, yielding a wide bandwidth with bandpass responses. The proposed antenna can be used at a frequency band of 26-32 GHz. The bending behaviors of the antennas with and without director elements were analyzed. The bending effect of the antenna should be considered when calculating the gain loss and bandwidth reduction. Inkjet printing on LCP substrates provides a low-cost, compact, and flexible packaging application that can be used in probable and flexible communication technology.

23 Sep 2014
TL;DR: In this article, a 6x6 element, dual-linear polarized array with beamformer that operates from 8 to 40 GHz is described. And the beamformer includes baluns that feed the dual-polarized differential antenna elements and reactive splitter networks that also cover the full frequency range of operation.
Abstract: Planar antennas based on tightly coupled dipole arrays (also known as a current sheet antenna or CSA) are amenable for use as electronically scanned phased arrays. They are capable of performance nearing a decade of bandwidth. These antennas have been demonstrated in many implementations at frequencies below 18 GHz. This paper describes the implementation using a relatively new multi-layer microfabrication process resulting in a small, 6x6 element, dual-linear polarized array with beamformer that operates from 8 to 40 GHz. The beamformer includes baluns that feed the dual-polarized differential antenna elements and reactive splitter networks that also cover the full frequency range of operation. This antenna array serves as a reflector feed for a multi-band instrument designed to measure snow water equivalent (SWE) from airborne platforms. The instrument has both radar and radiome try capability at multiple frequencies. Scattering-parameter and time-domain measurements have been used to characterize the array feed. Radiation patterns of the antenna have been measured and are compared to simulation. To the best of the authors' knowledge, this work represents the most integrated multi-octave millimeter-wave antenna feed fabricated to date.

Journal ArticleDOI
TL;DR: In this article, a low-length (10 mm) frequency-independent (4.5 GHz) beamforming balun was proposed for planar log-periodic dipole array antenna (PLPDA).
Abstract: A new balun used for feeding a planar log-periodic dipole array antenna (PLPDA) is proposed. This balun, which is based on mode conversion, converts gradually the transmission mode from quasi- TEM (coaxial cable) to full TEM (balanced line), with an accessible excitation current property (ECP), which is not achievable in classical feeding techniques (infinite or self balun). To validate this approach, an ultra-wideband (UWB) PLPDA antenna was designed with these balun structures for operating in the L and S bands (1-4 GHz) and the results were compared in terms of reflection coefficient and radiation pattern. A PLPDA antenna with a mode converter balun was fabricated. Results show that the proposed balun is a low length (10 mm) frequency-independent (4.5 GHz based on |S11|<-10 dB) device useful for feeding the UWB PLPDA antenna. Moreover, antenna's ECP can be modified, which is necessary for phase centre variation compensation.

Journal ArticleDOI
TL;DR: In this paper, a high-power terahertz solid-state amplifier fabricated using 0.25 μm InP heterojunction bipolar transistor (HBT) technology is reported.
Abstract: A high-power terahertz solid-state amplifier fabricated using 0.25 μm InP heterojunction bipolar transistor (HBT) technology is reported. This amplifier utilies a novel defective-ground four-way balun to combine differential amplifier chains for a total output device periphery of 40 μm. A significant amount of power of ∼10 mW is obtained at 305 GHz with better than 20 dB small-signal gain.

Journal ArticleDOI
TL;DR: In this article, a printed wideband Yagi-Uda antenna with a novel folded dipole driver is proposed, which consists of a foldable dipole and a microstrip feedline which functions as an internal balun to determine its wide impedance bandwidth.
Abstract: In this paper, a printed wideband Yagi-Uda antenna with a novel folded dipole driver is proposed. The folded dipole driver is comprised of a folded dipole and a microstrip feedline which functions as an internal balun to mainly determine its wide impedance bandwidth. With the optimized parameters, an operating band of 1:69GHz » 2:72GHz can be obtained. Besides the folded dipole driver, the broadband printed Yagi-Uda antenna also consists of three directors and a re∞ector. Its wideband performance is mainly determined by the folded dipole driver, while the re∞ector and directors improve its performance slightly. By optimizing the geometrical parameters of the folded dipole driver, a bandwidth of 61.8% (1:53GHz » 2:93GHz) for return loss being higher than 10dB is achieved. The proposed printed Yagi-Uda antenna is realized on FR4 substrate with a measured operating bandwidth of 62% (1:51GHz » 2:94GHz), a ∞at gain (5:6dB » 7:3dB), more than 10dB front-to-back ratio and lower than i15dB cross-polarization level.

Journal ArticleDOI
TL;DR: In this article, a dual-band balun is presented based on a 4-port symmetrical network, and even-odd-mode analysis is used to analyse the balun's performance.
Abstract: A novel dual-band balun is presented. The designed 3-port balun is based on a 4-port structure with the fourth port terminated as an open end. Being a 4-port symmetrical network, even–odd-mode analysis is used to analyse the balun's performance. Based on the derived explicit design equations, a balun is designed to operate at 1.1 and 2 GHz. Numerical simulations show a low reflection coefficient S 11, equal magnitude of −3 dB as well as 180° phase difference at the output ports. To validate the theoretical and numerical simulations, the proposed balun is fabricated on the FR4 Isola printed circuit board and measurement results match well with the design theory.

Journal ArticleDOI
TL;DR: In this article, a novel impedance-transforming coupled-line coupler with strong coupling coefficient is proposed for microstrip baluns, which has many advantages including planar structure without any via holes, strong coupled lines, and wide operation bandwidth.
Abstract: A novel impedance-transforming coupled-line coupler with strong coupling coefficient is proposed in this paper. Its analytical design methodology and applications to microstrip baluns are presented. For demonstration purposes, four numerical examples of this proposed impedance-transforming coupler with different terminated impedances are given. The calculated results show that this proposed coupler not only matches two different groups of terminated impedances but also covers the total power-dividing ratio range from 0 dB to infinite value. The measured results of the fabricated coupler verify the proposed design approach. Finally, this kind of coupler is used to construct a novel planar microstrip balun. This proposed balun has many advantages including planar structure without any via holes, strong coupled lines, and wide operation bandwidth. The experimental results of this proposed balun operating at approximately 2 GHz demonstrated these proposed ideas.

Journal ArticleDOI
Mi Zhou1, Jin Shao1, Bayaner Arigong1, Han Ren1, Jun Ding1, Hualiang Zhang1 
TL;DR: In this paper, two types of microwave baluns with generalized structures are presented, and the Even-odd mode method is applied to analyze the performance of these baluns, which match well with the theoretical analysis.
Abstract: In this letter, two types (Type-I and Type-II) of microwave baluns with generalized structures are presented. Different from the conventional transmission-line-based baluns where λ/2 transmission lines or λ/4 microstrip lines are used, the proposed baluns are constructed by transmission lines with arbitrary electrical lengths. Both of the two types of baluns are designed based on a symmetric four-port structure with one of the ports open-ended. Even-odd mode method is applied to analyze the performance of these baluns. Specifically, for the Type-I design, a symmetrical impedance transformer is employed to realize the desired flexible balun function. For the Type-II design, an asymmetric impedance transforming network is applied, and a compact size is achieved. Analytical design equations have been derived for both designs. Based on these equations, two different baluns (Type-I and Type-II) have been designed, fabricated and measured. The measurement results match well with the theoretical analysis, which practically proves the design theory.

Proceedings ArticleDOI
01 Jun 2014
TL;DR: In this article, a phase-reversible variable gain amplifiers (VGAs) were used for simultaneous amplitude and polarity control of a vector-sum phase shifter with a full 360° phase range.
Abstract: A 05-6 GHz CMOS vector-sum phase shifter with a full 360° phase range is presented Employing phase-reversible variable gain amplifiers (VGAs), for simultaneous amplitude and polarity control, the phase shifter realizes a continuously tunable phase shift of 360° with only one DC control voltage and single-ended I- and Q-signals A maximum gain of 11 dB is measured with a 2-dB gain variation over the 05-6 GHz band The root-mean-square (RMS) amplitude and phase error are less than 095 dB and 7° The measured in-band noise figure (NF) is better than 13 dB Wideband input and output matching are also achieved throughout the entire band Operating at 15 V, the entire circuit consumes 275 mW To the best of the authors' knowledge, it is the first time the phase-reversible VGA is used to realize a full-360° vector sum phase shifter, which eliminates the need for an input balun and a complicated control circuit

Journal ArticleDOI
TL;DR: An improved method of more than halving the turn on frequency of a 4-arm log-periodic (LP) antenna for dual-circularly polarized (CP) bidirectional use is demonstrated.
Abstract: An improved method of more than halving the turn on frequency of a 4-arm log-periodic (LP) antenna for dual-circularly polarized (CP) bidirectional use is demonstrated. The ground plane currents of a slot-LP are manipulated by varying “ground plane” shape to form a ring-turnstile-slot LP aperture and thus extend the overall antenna bandwidth. The proposed concept is used to design and fabricate an antenna that is 2.3 times smaller than the conventional 4-arm LP and works from 500 MHz to 3 GHz. Microstrip impedance transformer/balun is used to feed the LP thus allowing for bidirectional use and much simpler beamforming network for dual-polarized operation. VSWR and far-field behavior of the antenna are characterized and its high-power thermal stability is demonstrated through a high-power test. The advantages over the previously designed ring-turnstile-LP configuration are highlighted and the design principles undertaken to make the antenna high-power capable are illustrated. The prototyped antenna is meant not only to illustrate the proposed concept but also as a viable high-power bidirectional antenna.

Journal ArticleDOI
TL;DR: In this article, a novel method allowing for improvement of input match and output balance of Marchand balun with connecting line has been presented, which allows for achieving an arbitrary impedance transformation ratio even for the circuit having a long connecting line.
Abstract: A novel method allowing for improvement of input match and output balance of Marchand balun with connecting line has been presented. The proposed compensation technique together with the ideal Marchand balun design formulas allow for achieving an arbitrary impedance transformation ratio even for the circuit having a long connecting line. The theoretical analysis has been verified by EM simulations and measurements of a Marchand balun composed of 3 dB coupled-line sections and 30° transmission line operating at the center frequency f 0 = 1.15 GHz and terminated at input and outputs with 50 Ω and 100 Ω, respectively.

Journal ArticleDOI
TL;DR: In this paper, a branch-line-coupler balun has been proposed for fast detection of Ic and Id from the differential-mode signaling, with miniaturization effect and possibility of cheaper fabrication.
Abstract: We proposed a new PCB-type ‘common-mode current(I c ) and differential-mode current(I d ) detector’ working for fast detection of Ic and Id from the differential-mode signaling, with miniaturization effect and possibility of cheaper fabrication. In order to realize this device, we suggest a branch-line-coupler balun having a composite right- and left-handed(CRLH) one-layer microstrip phase-shifting line as compact as roughly λg/14. The presented balun obviously is different from the conventional bent-&-folded delay lines or slits on the ground for coupling the lines on the top and bottom dielectrics. As we connect the suggested balun output ports of the differential-mode signal lines via the through-port named U and coupled-port named L, I c and I d will appear at port Δ and port Σ of the present device, in order. The validity of the design scheme is verified by the circuit-and numerical electromagnetic analyses, and the dispersion curve proving the metamaterial characteristics of the geometry. Besides, the examples of the I c and I d indicator are observed as the even and odd modes in differential-mode signal feeding. Also, the proposed device is shown to be very compact, compared with the conventional structure.

Journal ArticleDOI
TL;DR: In this paper, a balanced diplexer and a balun Diplexers with high common-mode suppression and differential-mode isolation were proposed for the two channels of 2.45 GHz WLAN and 3.55 GHz WiMAX.
Abstract: A balanced diplexer and a balun diplexer, both designed for the two channels of 2.45-GHz WLAN and 3.55-GHz WiMAX, are proposed with high common-mode (CM) suppression and differential-mode (DM) isolation in this paper. For the balanced diplexer, balanced BPFs for the two desired channels were first designed using stepped-impedance slot-line resonators (SISLRs). Through two T-junctions, the two BPFs were subsequently combined to form a three-balanced-port diplexer having six single-ended ports. Such a balanced diplexer can be easily converted into a balun diplexer with one single-ended and two balanced ports. For that purpose, one of the T-junctions and its associated two feeding lines are removed, and the feeding lines connected to the other T-junction are modified. For both diplexers, the measured CM suppressions (DM isolations) are larger than 54.3 (39.5), 52.2 (44.5), and 40.7 (38.7) dB, respectively, in the lower channel, the upper channel, and the displayed frequency range of 1–6 GHz. A satisfactory a...

Patent
22 Jan 2014
TL;DR: In this paper, a novel broadband printed dipole antenna with a branch wire integrated with a feed balun is presented, where the branch wire is equivalent to a series resistor, and is used for improving the matched impedance.
Abstract: The invention discloses a novel broadband printed dipole antenna with a branch wire integrated with a feed balun. The novel broadband printed dipole antenna comprises an SMA (Shape Memory Alloy) joint, a dielectric-slab, a radiating element and a microstrip line feed integrated balun, wherein the radiating element is provided with a slotting seam; dual radiation arms are formed on both sides of the slotting seam; the microstrip line feed integrated balun is provided with a branch wire; the branch wire is equivalent to a series resistor, and is used for improving the matched impedance. According to the novel broadband printed dipole antenna, the VSWR (Voltage Standing Wave Ratio) is less than or equal to 1.5, and the relative bandwidth is up to 58.7 percent (1.65-3.0GHz); compared with other bandwidth extension technologies (such as a parasitic patch increasing technology), the novel broadband printed dipole antenna has the advantages that design is made on the basis of not changing the original size of the antenna, so that the bandwidth of the antenna is improved, other performance of the antenna (such as gain and cross polarization level) is not influenced, and the occupied space is reduced; the novel broadband printed dipole antenna has the advantages of simple structure, convenience, practicability, wide adaptability and the like.

Journal ArticleDOI
TL;DR: In this article, a millimeter-wave passive balun on silicon substrate with small size and good balance is presented. And the reason for the imbalance of the balun is analyzed and a novel method using two grounded T bars beneath the coupled lines to tune the balance is proposed.
Abstract: The analysis and design of a millimeter-wave passive balun on silicon substrate with small size and good balance is presented. The reason for the imbalance of the balun is analyzed and a novel method using two grounded T bars beneath the coupled lines to tune the balance is proposed. The balun was fabricated in a 65 nm CMOS process, by using broadside coupled lines with small separation, the length of balun is reduced, resulting in a size of only 0.01 mm2. In the 57-67 GHz band, the measured amplitude imbalance is less than 0.5 dB and the phase imbalance is less than 1 °. This method for optimizing the imbalance of balun is efficient and it does not increase the size of balun.