Showing papers on "Return loss published in 2017"
TL;DR: Both measured and simulated return loss characteristics of the optimised antenna show that it satisfies the requirement of 2.4/5.8 GHz WLAN and 3.5 GHz WiMAX antenna applications.
Abstract: In this study, the authors present a simple reconfigurable multiband antenna with two PIN diode switches for worldwide interoperability for microwave access (WiMAX)/wireless local area networks (WLAN) applications. The antenna permits reconfigurable switching in up to ten frequency bands between 2.2 and 6 GHz, with relative impedance bandwidths of around 2.5 and 8%. The proposed antenna has been simulated using computer simulation technology microwave studio software and fabricated on an FR-4 substrate. It is compact, with an area of 50 × 45 mm
2
, and has a slotted ground substrate. Both measured and simulated return loss characteristics of the optimised antenna show that it satisfies the requirement of 2.4/5.8 GHz WLAN and 3.5 GHz WiMAX antenna applications. Moreover, there is good agreement between the measured and simulated results in terms of radiation pattern and gain.
105 citations
TL;DR: This communication presents a novel cactus-shaped ultrawideband (UWB) monopole antenna fabricated on liquid crystal polymer (LCP) that presents very consistent omnidirectional patterns throughout the UWB frequency range.
Abstract: This communication presents a novel cactus-shaped ultrawideband (UWB) monopole antenna fabricated on liquid crystal polymer (LCP). The proposed antenna is a very compact design, since it can be fabricated on a board with dimensions only $20\times28$ mm $^{2}$ , while the three linear segments that comprise the cactus-shaped monopole provide a direct control on antenna matching. The proposed antenna is operating from 2.85 to 11.85 GHz and it presents very consistent omnidirectional patterns throughout the UWB frequency range. Return loss and pattern measurements are presented and the operation principles are discussed in detail. The simplicity of this topology, with the easily controllable return loss, allows for its easy implementation for various UWB subband designs, just by building suitable monopole versions, for which the only difference is the length of the three linear segments.
77 citations
01 Jul 2017
TL;DR: The proposed single band antenna and simulated result on return loss, VSWR, surface current and 3D radiation pattern is presented and shows the return loss −40.99dB at 60 GHz millimeter wave 5G wireless application presented.
Abstract: This proposed paper, a single band microstrip patch antenna for 5G wireless application is presented. This proposed antenna is suitable for the millimeter wave frequency. The single band antenna consist of new H slot and E slot loaded on the radiating patch with the 50 ohms microstrip line feeding used. This single band antenna is simulated on a Rogers RT5880 dielectric substrate have relative permittivity 2.2, loss tangent 0.0009, and height 1.6mm. The antenna is simulated by Electromagnetic simulation, computer software technology Microwave studio. The proposed single band antenna and simulated result on return loss, VSWR, surface current and 3D radiation pattern is presented. The simulated antenna shows the return loss −40.99dB at 60 GHz millimeter wave 5G wireless application presented.
64 citations
TL;DR: In this article, a wideband circularly polarized (CP) dielectric resonator antenna with filtering response was proposed in this communication, which achieved an average gain of 6 dBic with a variation less than 1 dB.
Abstract: A wideband circularly polarized (CP) dielectric resonator antenna (DRA) with filtering response was proposed in this communication. To combine additional filtering and harmonic suppression functions within an antenna while realizing circular polarization, a new wideband filtering quadrature coupler was implemented to feed a hollow DRA. The filtering quadrature coupler was based on a snowflake shaped patch, whose operating modes can be flexibly controlled by the loading slots. Quarter wavelength coupled line sections were introduced to the coupler, realizing simultaneously wide bandwidth, excellent bandpass filtering, and wide harmonics suppression characteristics. For demonstration, a filtering CP antenna operating at 1.8 GHz was designed, fabricated, and measured. Reasonable agreement between simulated and measured results was observed. The prototype exhibited excellent bandpass filtering characteristics together with a wide overlapping bandwidth of 27.8%, within which the axial ratio value was less than 3 dB, and return loss was better than 12.4 dB. Over the same band, an average gain of 6 dBic with a variation less than 1 dB was achieved. A rejection level larger than 19 dB was found within the suppression band up to the third harmonic.
59 citations
TL;DR: In this paper, a low-profile and broadband absorber based on capacitive surfaces is proposed and implemented, which exhibits good absorption at −10 dB return loss over the fractional bandwidth of 82.5% −117.4%.
Abstract: Low-profile and broadband absorbers based on capacitive surfaces are proposed and implemented. First, the impedance of a dielectric substrate and capacitive surface is analyzed separately to characterize the surface impedance. The capacitive surfaces are therefore achieved with the combination of two ring resonators and used to design a three-fold and four-fold symmetric absorber. The resulting absorbers, with the thickness of about 0.076 $\;{\lambda _L}$ at the lowest operating frequency, exhibit good absorption at −10 dB return loss over the fractional bandwidth of 82.5%–117.4%. For demonstration, one prototype of the proposed absorber was fabricated and measured, and good agreement is observed.
55 citations
TL;DR: This synthesis method simplifies the implementation of the network in the distributed form as compared with the LC low-pass matching network where equivalences are necessarily required in the rough conversion from lumped-to-distributed elements.
Abstract: A new synthesis method for the design of broadband impedance matching network has been introduced to match the transistor input. The proposed matching network would be a realistic alternative to those that are frequently designed in low-pass structure. Easy-to-use design equations are given for this filter-based matching network. The required impedance of the stubs and the connecting lines can be directly calculated from the equations. This synthesis method simplifies the implementation of the network in the distributed form as compared with the LC low-pass matching network where equivalences are necessarily required in the rough conversion from lumped-to-distributed elements. The high-efficiency mode of operation is guaranteed by the constructed output low-pass matching network, since the LC low-pass network can provide the prescribed load terminations at fundamental frequencies and at harmonics. A commercially available 10-W GaN HEMT device (CGH40010) was used in this investigation. The proposed broadband power amplifier exhibits band-pass Chebyshev response in S-parameter measurements, and yields good gain flatness (±0.5 dB) and input return loss (>13 dB). Power-added efficiency of 58%–72% has been measured in large-signal measurements. After digital predistortion, the measured adjacent channel leakage power ratio is below −50 dBc at ±5- and ±10-MHz offset, when driven by 5- and 10-MHz WCDMA signals at 7-dB power back off.
54 citations
TL;DR: In this paper, a 2-and 3-pole bandpass filters with a wide frequency tuning range (tuning ratio > 3) and a constant bandwidth using switchable varactor-tuned resonators are presented.
Abstract: This paper reports on tunable 2- and 3-pole bandpass filters with a wide frequency tuning range (tuning ratio >3) and a constant bandwidth using switchable varactor-tuned resonators. The wide center frequency tuning range is obtained using p-i-n diodes to switch in and out quarter-wavelength ( $\lambda $ /4) or half-wavelength ( $\lambda $ /2) resonators for low-band or high-band modes, without increasing the tuning capacitance range of the varactors. A combination of electric and magnetic coupling is utilized to realize a near constant absolute bandwidth across the tuning range. A switchable feed line with a fixed matching capacitance is used to realize the external coupling. Two filters are designed and fabricated on a Duroid substrate with $\varepsilon _{r} = 2.2$ and $h =0.787$ mm. For the 2-pole filter, the center frequency is tuned from 550 to 1900 MHz while maintaining a 3-dB bandwidth of 92 ± 6 MHz, insertion loss of 3.2~4.4 dB, and return loss of better than 15 dB. For the 3-pole filter, the center frequency is tuned from 540 to 1800 MHz while maintaining a 3-dB bandwidth of 89 ± 4 MHz, insertion loss of 4~5.4 dB, and return loss of better than 12 dB. For both filter types, the third-order intercept point and 1-dB compression point ( $P_{\mathrm {1~dB}})$ are 11 and 7 dBm, respectively. The rejection level at 200-MHz offset frequency from the passband center frequency is better than 25 and 41 dB for 2- and 3-pole filters, respectively, across the entire tuning range. To the best of our knowledge, this planar bandpass filter exhibits the widest tuning range with a near-constant bandwidth.
52 citations
TL;DR: In this article, an ultra-wideband (6-18 GHz) phased-array antenna with a beam scanning angle of ±28° is proposed, and a step-by-step design procedure consisting of beamforming network (BFN), end-launcher feed adapter, and the radiating element is presented.
Abstract: An ultra-wideband (6–18 GHz) phased-array antenna with a beam scanning angle of ±28° is proposed. A step-by-step design procedure consisting of beamforming network (BFN), end-launcher feed adapter, and the radiating element is presented. Microstrip Rotman lens has been designed to act as the BFN, and optimized to achieve minimum phase-error over the whole frequency range. In order to satisfy the condition needed for avoiding grating lobes, as well as achieving a wide radiation bandwidth and a high power handling capability, an $E$ -plane double-ridged horn antenna is used as the radiating element. A novel wideband end-launcher coaxial to double-ridged waveguide transition has also been developed for connecting the BFN to the antenna array. Extensive optimization procedures have been applied to the end-launched adapter together with the antenna to achieve the best return loss over the frequency band of operation. The whole system has been simulated using CST full-wave simulator. An excellent agreement between the measurements of the fabricated system and the simulated results is observed.
48 citations
TL;DR: In this article, a two-section wideband hybrid coupler with short-circuited coupled lines in the middle branch is demonstrated. But the proposed two-sections coupler has the widest fractional bandwidth (FBW) than other two or even three section hybrid couplers modified from branch-line coupler.
Abstract: Two section wideband hybrid coupler with short-circuited coupled lines in the middle branch is demonstrated. The coupled lines are designed with a parallel-coupled 3-line, which has tight coupling and symmetric transmission phase over the center frequency. Without defected ground planes and a multilayer process, the proposed two-section coupler has the widest fractional bandwidth (FBW) than other two or even three section hybrid couplers modified from branch-line couplers. The designed wideband coupler has 55% FBW at the center frequency of 1.9 GHz. The bandwidth is limited by 1-dB power imbalance and the worst return loss, isolation, and phase imbalance within the bandwidth are 20.1 dB, 20.8 dB, and 3.2°, respectively.
42 citations
01 Aug 2017-Microsystem Technologies-micro-and Nanosystems-information Storage and Processing Systems
TL;DR: In this paper, a compact dual band and wideband slot loaded multilayered patch antennas are presented for WLAN and WiMAX applications, where antenna parameters such as return loss, radiation pattern, gain, frequency ratio, VSWR, efficiency, group delay and beamwidth are discussed.
Abstract: In this proposed work a compact dual band and wideband slot loaded multilayered patch antennas are presented for WLAN and WiMAX applications. The antenna parameters such as return loss, radiation pattern, gain, frequency ratio, VSWR, efficiency, group delay and beam-width are discussed. The bandwidth of the proposed dual band antenna at lower resonant frequency is 9.53 % (simulated) and 13.2 % (experimental) whereas at upper resonance frequency is 6.95 % (simulated), and 13.32 % (experimental) while for wideband it is 26.7 % (simulated) and 25.09 % (experimental). The proposed antenna structures are simulated by HFSS tool, fabricated and the simulated results are verified by experiment.
41 citations
TL;DR: Four pairs of microstrip MIMO conformal antennas of 35 GHz with Eight-element microstrip Taylor antenna array with series-feeding not only achieves the deviation of the main lobe of the pattern but also increases the bandwidth of the antenna array and reduces sidelobe.
Abstract: With the development of wireless communication technology, 5G will develop into a new generation of wireless mobile communication systems. MIMO (multiple-input multiple-output) technology is expected to be one of the key technologies in the field of 5G wireless communications. In this paper, 4 pairs of microstrip MIMO conformal antennas of 35 GHz have been designed. Eight-element microstrip Taylor antenna array with series-feeding not only achieves the deviation of the main lobe of the pattern but also increases the bandwidth of the antenna array and reduces sidelobe. MIMO antennas have been fabricated and measured. Measurement results match the simulation results well. The return loss of the antenna at 35 GHz is better than 20 dB, the first sidelobe level is −16 dB, and the angle between the main lobe and the plane of array is 60°.
TL;DR: In this paper, a new microstrip line to groove gap waveguide (GGW) transition has been proposed, where the microstrip section is extended into the cavity without any requirement of contact with the GGW, and measured results for the $V$ -band transition show a relative bandwidth of 26% for a return loss better than 10 dB.
Abstract: In this letter, a new microstrip line to groove gap waveguide (GGW) transition has been proposed. The transition is based on a resonant cavity, which efficiently helps to couple the field from microstrip line to GGW. In this transition, the microstrip section is extended into the cavity without any requirement of contact with the GGW. Such contactless transition inside the waveguide is advantageous as it allows easy packaging and integration of millimeter wave circuitry with gap waveguide components such as filters and array antennas. Alumina ( $\epsilon _{r}=9.9$ ) was used as the microstrip substrate for the proposed transition in this letter. Measured results for the $V$ -band transition show a relative bandwidth of 26% for a return loss better than 10 dB. The maximum insertion loss of the manufactured back-to-back prototype is found to be 1.32 dB, which also includes the losses of a 5.45-mm-long microstrip line on an Alumina substrate. After subtracting the losses in the microstrip section, the losses in a single transition are found to be varying between 0.145 and 0.38 dB over the bandwidth.
TL;DR: A new technique using two p-i-n diodes to switch between two channels of a Tunable diplexer with constant return loss is proposed to design a tunable bandpass filter (BPF) with wide frequency tuning range (FTR).
Abstract: In this paper, a new technique using two p-i-n diodes to switch between two channels of a tunable diplexer with constant return loss is proposed to design a tunable bandpass filter (BPF) with wide frequency tuning range (FTR). The used third-order tunable diplexer with two independently tuned channels consists of one common varactor-tuned lumped-element dual-resonance resonator and two varactor-tuned LC resonators. The ports of its two channels are connected by a single-pole double-throw switch, so that one port of the tunable BPF is constituted. And its common port serves as the other port of the tunable BPF. In the switched tunable diplexer design, its direct current (dc) bias voltages are also appropriately selected to improve the in-band and out-of-band performances of the tunable BPF. As examples, a third-order tunable diplexer with constant return loss of 15 dB is first designed. The measured results show that the 3 dB cutoff frequency of its lower channel can be tuned from 0.5 to 1.02 GHz, while the 3 dB cutoff frequency of its upper channel can be tuned from 1.01 to 1.78 GHz. Then, a tunable BPF is designed, and its 3 dB cutoff frequency covers from 0.485 to 1.82 GHz. The proposed tunable BPF exhibits good return loss, wide FTR, and compact size.
TL;DR: By exploring embedding transversal signal-interference sections in a Wilkinson power divider, this letter proposes a novel methodology for the filter and power Divider co-design that realizes simultaneous power division and filtering in a single uniplanar circuit.
Abstract: By exploring embedding transversal signal-interference sections in a Wilkinson power divider, this letter proposes a novel methodology for the filter and power divider co-design. The structure realizes simultaneous power division and filtering in a single uniplanar circuit. In this letter, the equations as well as the detailed design methodology are given. In the last section, simulations and experiments are carried out, the results of which show a filtering power-division performance with 90% bandwidth (15-dB return loss) and two transmission zeros at the passband edges.
TL;DR: In this paper, a compact rectangular-ring patch antenna with dual bands and dual circular polarisation is proposed for BeiDou navigation satellite system (BDS) application in which two pairs of inverted-L shaped strips and perturbation structures are inserted in two radiation patches, respectively, to achieve circularly polarised radiation in dual bands.
Abstract: A compact rectangular-ring patch antenna with dual bands and dual circular polarisation is proposed for BeiDou navigation satellite system (BDS) application in this study. The compactness of the proposed antenna can be realised through using a rectangular-ring radiation patch for the higher band and a meandered-line-shaped ring radiation patch for the lower band. The radiation patches are stacked and printed, respectively, on the two layers of substrate separated by an air gap. Two pairs of inverted-L shaped strips and perturbation structures are inserted in two radiation patches, respectively, to achieve circularly polarised radiation in dual bands. Specifically, arc-shaped coupled feeding lines are employed to obtain preferable impedance matching. Simulated and measured results show a good performance such as a compact size of 0.201
λ
g
× 0.201
λ
g
× 0.076
λ
g
, satisfactory 10-dB return loss bandwidths (1595-1632 MHz, 2395-2574MHz) and desirable directional radiation patterns with the antenna gain of nearly 4.3 dBic at 1615.68MHz and 6.4 dBic at 2491.75MHz.
TL;DR: In this paper, a varactor-based coupler structure was proposed for reconfigurable operating frequency, power-dividing ratio, and coupler to/from crossover responses.
Abstract: This paper proposes a varactor-based coupler structure that allows for reconfigurable operating frequency, power-dividing ratio, and coupler to/from crossover responses. Particularly, this coupler can theoretically realize perfect impedance matching and port isolation at all tuning states. The coupler analysis, design equations, and design graphs were conducted, given, and discussed in detail. For demonstration purposes, two prototypes were experimentally developed and characterized. The first quadrature coupler demonstrates a frequency-tuning range from 0.632 to 1.5 GHz with a constant power-dividing ratio of −3 dB, 20-dB isolation, and >14-dB return loss. In the second prototype, for the phase error 19 dB, the power-dividing ratio was tuned from −6.4 to 20.5 dB at 1 GHz, yielding a 26.9-dB tuning range and crossover characteristics at low bias voltages. Measured and simulated results are in good agreement.
TL;DR: In this paper, a nonresonant circular polarization selective structure (CPSS) based on multiple layers of stacked meander line sheets arranged closely after each other is proposed.
Abstract: We present a nonresonant circular polarization selective structure (CPSS) based on multiple layers of stacked meander line sheets arranged closely after each other. The structure has a total thickness of 13.5 mm (0.68 wavelengths at center frequency 15 GHz) and is realized by cascading printed circuit boards interspaced with a low-permittivity foam material, and the different layers are bonded together with thin layers of adhesive spray. A design procedure is presented that can be used to optimize the proposed structure based on its target band of operation. Based on this method, an optimized design has been simulated, and the structure shows a return loss and an insertion loss better than 0.5 dB, and axial ratio in transmission and reflection better than 0.78 dB, over a fractional bandwidth of 45.8% at normal incidence, fully covering the Ku-band 12–18 GHz. The functionality of the structure has been verified experimentally through measurements, both in reflection and transmission, with a total bandwidth of 42.0%, covering 86.7% of the Ku band. The simulated performance at oblique angles of incidence shows significant improvements when compared to classical resonant CPSSs.
TL;DR: In this article, a compact filtering power divider composed of two quartermode circular cavities based on the substrate integrated waveguide is proposed, which achieves a selective bandpass filtering response and improves the performance of the upper stopband.
Abstract: A compact filtering power divider composed of two quarter-mode circular cavities based on the substrate integrated waveguide is proposed. Two extra perturbing via-holes added in each side of the quarter-mode circular cavity achieve a selective bandpass filtering response and improve the performance of the upper stopband. The proposed FPD operates at 9.1 GHz with a 3 dB fractional bandwidth of 19.8%. The insertion loss in operating band is <; 1.6 dB and the input return loss is better than 16 dB. The amplitude and phase imbalances between the two outputs are measured better than 0.6 dB and 3.5°, respectively. The measured results exhibit good agreement with the simulated ones.
TL;DR: In this paper, a miniaturized multiband monopole antenna based on rectangular-shaped Complementary Split Ring Resonators (CSRRs) with offset-fed microstrip line is proposed for Global System for Mobile Communication (GSM) and Wireless Local Area Network (WLAN) applications.
Abstract: A miniaturized multiband monopole antenna based on rectangular-shaped Complementary Split Ring Resonators (CSRRs) with offset-fed microstrip line is proposed for Global System for Mobile Communication (GSM) and Wireless Local Area Network (WLAN) applications The proposed antenna is fabricated on a FR-4 substrate having a dielectric constant ( ɛ r ) of 44 within a small size of 1918 × 2264 × 16 mm 3 CSRRs in the monopole antenna create a multiband characteristics and bandwidth improvement, which is analyzed by use of the precise quasi-static design equations and electromagnetic simulation software (HFSS version 13) By selecting a proper offset-fed microstrip line, it is capable to achieve 50 Ω characteristic impedance and good impedance matching The parameter extraction procedure of the metamaterial property of the CSRRs is enlightened in detail, by which the negative permittivity existence and the new resonance frequencies are verified Simulated and measured result coincides with each other The measured H-Plane (azimuthal plane) exhibits omnidirectional radiation pattern and E-plane (elevation plane) shows a dipole like bidirectional radiation pattern The proposed antenna has adequate advantages, including simple design, small size, lower return loss and capable of multiband operations
TL;DR: In this article, the authors proposed the design of circulators based on spoof surface plasmon polaritons (SSPP), where the center conductor is replaced with a blade structure that supports the SSPP mode and exhibits a shorter wavelength and larger wave vector.
Abstract: In the letter, we propose the design of circulators based on spoof surface plasmon polaritons (SSPP). Rather than striplines, the center conductor is replaced with a blade structure that supports the SSPP mode and exhibits a shorter wavelength and larger wave vector. To enhance the efficiency, a matching transition is employed between the coplanar waveguide and the blade structure. With biased ferrites attached on both the top and bottom sides, the blade structure shows good nonreciprocal properties. The simulation results indicate that in the 5.0-6.6 GHz frequency range, the isolation and return loss reaches 15 dB and the insertion loss is less than 0.5 dB. Since the circulator utilizes the SSPP mode, which exhibits a shorter wavelength than its analogous stripline mode, the size of ferrites, and thus the size of the circulator, can be reduced. Our work provides an effective route to the design of compact, broadband circulators.
TL;DR: In this article, a contactless transition from a high-permittivity microstrip line to an air-filled waveguide (WG) has been impedance-matched over a large simulated relative bandwidth of 38% ( $W$ -band, 75-110 GHz).
Abstract: A contactless transition from a high-permittivity microstrip line ( $\epsilon _{r}=9.9$ ) to an air-filled waveguide (WG) has been impedance-matched over a large simulated relative bandwidth of 38% ( $W$ -band, 75–110 GHz). The transition couples the electromagnetic fields directly from the Monolithic Microwave Integrated Circuit (MMIC’s) microstrip line via an Substrate Integrated Waveguide and an off-chip stub section to a ridge WG section. The novel structure is low loss and suits pick-and-place assembly techniques of mm-wave MMICs inside metal WGs. The design process is detailed and manufacturing tolerances of the alumina prototype printed circuit board are discussed. The measured back-to-back structure retains an appreciable insertion loss smaller than 0.8 dB for a single transition and a fractional bandwidth of 28% (72–95 GHz) over which the return loss is greater than 10 dB.
TL;DR: A single-feed dual-band dual-sense circularly polarized (CP) stacked patch antenna with a small frequency ratio is proposed for Chinese 842.5/922.5-MHz radio frequency identification (RFID) reader applications.
Abstract: A single-feed dual-band dual-sense circularly polarized (CP) stacked patch antenna with a small frequency ratio is proposed for Chinese 842.5/922.5-MHz radio frequency identification (RFID) reader applications. Two elliptical-ring patches are configured orthogonally to operate at different frequency bands with different senses of circular polarization. A $\Pi $ -type dual-band complex impedance transformer is modified with asymmetric open-ended stubs to easily tune the input matching for both bands. Measured impedance bandwidth is 2.99% (824–849 MHz) for the lower band and 2.72% (908–933 MHz) for the upper band, in which the input return loss is greater than 10 dB. The measured 3-dB axial ratio (AR) bandwidths for the lower and upper bands are 1.07% (838–847 MHz) and 1.19% (918–929 MHz), respectively. The measured frequency ratio is 1.10. The measured gain is more than 4.5 dBic over both bands. Therefore, the proposed antenna can be a good candidate for Chinese RFID readers operating in the bands of 840–845 MHz and 920–925 MHz.
TL;DR: In this article, a liquid crystal (LC) based tunable microstrip line (ML) phase shifter featuring high performance is presented, and the experimental results show an electrically tunable differential phase up to 360° at 10GHz with an overall insertion loss <8.5 dB.
Abstract: © 2017 The Japan Society of Applied Physics.A liquid crystal (LC) based tunable microstrip line (ML) phase shifter featuring high performance is presented. The experimental results show an electrically tunable differential phase up to 360° at 10GHz with an overall insertion loss <8.5 dB. The device possesses a high figure-of-merit (FoM) of 64°/dB at 9.8GHz and 60°/dB between 7-10GHz. This is achieved by simultaneously considering both of the LC tuned phase and overall loss in the design. The proposed device utilizes the inverted meander ML technology to minimize its size. Taking into account the real fabrication procedure, a novel impedance matching structure is applied, and the measured return loss is considerably improved. The FoM and phase tuning property of the fabricated device as optimized are compared with the state-of-Art results published recently and show better performance for both of them.
TL;DR: In this paper, the authors presented a 60 GHz low-loss compact 4-b phase shifter in a 65-nm CMOS, which is based on a 1-b high-pass/low-pass structure and a 3-b switched-filter structure.
Abstract: This paper presents a 60-GHz low-loss compact 4-b phase shifter in a 65-nm CMOS. It is based on a 1-b high-pass/low-pass structure and a 3-b switched-filter structure, and employs fully custom-designed capacitors with a high quality factor for low insertion loss. The phase shifter with custom-designed capacitors reduces an insertion loss by 2.6 dB at 60 GHz. The average insertion loss is 8.1 dB at 60 GHz, and the return loss is better than 10.6 dB over a range of 57–66 GHz. The measured 16-output state of the fabricated phase shifter has a phase resolution of 22.5° with an rms phase error less than 5.5° over the 57–66 GHz range. The fabricated phase shifter has a compact core size of 0.42 mm $\times0.22$ mm. To the best of our knowledge, this phase shifter achieves the lowest insertion loss and the smallest core area of all the published 60-GHz 360° -coverage passive CMOS phase shifters.
TL;DR: In this article, a Ka-band waveguide magic-T with coplanar arms is presented, which uses an E-plane power divider and a ridge-waveguide transition.
Abstract: A Ka-band waveguide magic-T with coplanar arms is presented in this letter. By using an E-plane power divider and a ridge-waveguide transition, the four arms of the magic-T are placed in the same plane, which greatly simplifies the assembly. Compared to the previous method utilizing a microstrip-to-waveguide transition, the structure proposed in this letter achieved a higher power-handling capability because of all-metal elements. Over the frequency band of 28 to 36 GHz, the measured return loss of the input port and the isolation between the opposite ports are greater than 20 dB, indicating good characteristics of the proposed structure.
TL;DR: In this article, a sixteenth-mode substrate integrated waveguide (SMSIW) bandpass filter with complementary split-ring resonator (CSRR) is proposed.
Abstract: A novel sixteenth-mode substrate integrated waveguide (SMSIW) bandpass filter loaded with complementary split-ring resonator (CSRR) is proposed. The filter size is reduced by introducing the SMSIW circular cavity loaded with CSRR. The SMSIW occupies only 6.25% of the conventional substrate integrated waveguide with same resonant frequency. Further miniaturisation is achieved by loading the SMSIW circular cavities with CSRRs. The designed filter is centred at 2.45 GHz with a bandwidth of 8.2%. The measured minimum insertion loss is 0.9 dB and passband return loss is below 10 dB. Good agreement is achieved between simulated and measured results.
TL;DR: The reflection load consisting of two tunable capacitors and a quarter wavelength transmission line is utilized on a vertically installed planar structure to implement a new reflection-type phase shifter, which achieves wide bandwidth, wide tunable phase range, and a compact circuit size.
Abstract: Wide bandwidth, wide tunable phase range, and a compact circuit size are always desired for the tunable phase shifter utilized in the modern wireless communication system. However, the existing reflection-type phase shifter configurations cannot satisfy all these requirements simultaneously. To resolve these problems, the reflection load consisting of two tunable capacitors and a quarter wavelength transmission line is utilized on a vertically installed planar structure to implement a new reflection-type phase shifter. For demonstration, a reflection-type phase shifter is designed, fabricated, and measured. A wide bandwidth of 66.7% defined by 10-dB return loss had been achieved. Over the same band, a wide phase shift range up to 407° can be observed. Meanwhile, the fabricated circuit occupies a compact circuit size of ${0.26\lambda _{g} *0.37\lambda _{g}}$ .
TL;DR: A simple and efficient transition structure with tapered CPWs and gradient slots is proposed to realize high-efficiency and broadband excitation of the second mode of SSPPs for the first time, to the best of the authors' knowledge.
Abstract: A complementary structure based on coplanar waveguides (CPWs) with periodical etching slots is proposed to support spoof surface plasmon polaritons (SSPPs). In contrast to the traditional slotline-based complementary SSPP structure, a dispersion curve of the second mode by the proposed structure has a much lower starting point from the origin which exhibits greatly improved operating bandwidth. Moreover, tighter confinements of SSPPs in the region of small wave vectors corresponding to lower frequencies can be predicted from the dispersion analysis, which means enhancement of transmission efficiency. Then a simple and efficient transition structure with tapered CPWs and gradient slots is proposed to realize high-efficiency and broadband excitation of the second mode of SSPPs for the first time, to the best of our knowledge. Based on the proposed structure, a seamless connection between CPWs and the SSPP structure can be achieved. The measured insertion loss and return loss below 6.6 GHz is better than −0.86 and −13.62 dB, respectively. Furthermore, it can be seen from the measurement results that a 3 dB bandwidth ranges from 0 to 10.57 GHz, and the return loss is better than −10 dB from 0 to 8.96 GHz. The proposed structure can promote the development of plasmonic integrate circuits and functional devices at microwave frequencies.
TL;DR: The design of Modified Sierpinski Carpet Fractal Antenna which resonates at six frequencies 4.825, 5.455, 6.265 GHz and 6.145 GHz is described and good agreement with each other is found.
Abstract: The sudden growth in wireless communication area has increased the requirements of compact integrated antennas. This paper describes the design of Modified Sierpinski Carpet Fractal Antenna which resonates at six frequencies 4.825, 5.455, 6.265 GHz and 6.805, 8.02 and 9.145 GHz. Different performance parameters like radiation pattern, gain, Voltage Standing Wave Ratio, return losses are observed at all the frequencies. The FR4 glass epoxy with relative permittivity 4.4 and height 1.6 mm is used as substrate material. Antenna is fed by coaxial probe feed and simulated using ANSYS/ANSOFT HFSS V13 software. Proposed antenna has simple structure. Investigation is done between 1 and 10 GHz frequencies. The proposed antenna is fabricated and tested on the Vector Network Analyzer. The measured and simulated results of proposed antenna are compared and are found to be good agreement with each other.