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Showing papers on "Balun published in 2008"


Journal ArticleDOI
TL;DR: It is shown that a CS-stage with deep submicron transistors can have high IIP2, because the nugsldr nuds cross-term in a two-dimensional Taylor approximation of the IDS(VGS, VDS) characteristic can cancel the traditionally dominant square-law term in the IDs(V GS) relation at practical gain values.
Abstract: An inductorless low-noise amplifier (LNA) with active balun is proposed for multi-standard radio applications between 100 MHz and 6 GHz. It exploits a combination of a common-gate (CGH) stage and an admittance-scaled common-source (CS) stage with replica biasing to maximize balanced operation, while simultaneously canceling the noise and distortion of the CG-stage. In this way, a noise figure (NF) close to or below 3 dB can be achieved, while good linearity is possible when the CS-stage is carefully optimized. We show that a CS-stage with deep submicron transistors can have high IIP2, because the nugsldr nuds cross-term in a two-dimensional Taylor approximation of the IDS(VGS, VDS) characteristic can cancel the traditionally dominant square-law term in the IDS(VGS) relation at practical gain values. Using standard 65 nm transistors at 1.2 V supply voltage, we realize a balun-LNA with 15 dB gain, NF +20 dBm, while simultaneously achieving an IIP3 > 0 dBm. The best performance of the balun is achieved between 300 MHz to 3.5 GHz with gain and phase errors below 0.3 dB and plusmn2 degrees. The total power consumption is 21 mW, while the active area is only 0.01 mm2.

579 citations


Journal ArticleDOI
TL;DR: In this article, the authors proposed to merge an I/Q current-commutating mixer with a noise-canceling balun-LNA to realize a high bandwidth.
Abstract: This paper proposes to merge an I/Q current-commutating mixer with a noise-canceling balun-LNA. To realize a high bandwidth, the real part of the impedance of all RF nodes is kept low, and the voltage gain is not created at RF but in baseband where capacitive loading is no problem. Thus a high RF bandwidth is achieved without using inductors for bandwidth extension. By using an I/Q mixer with 25% duty-cycle LO waveform the output IF currents have also 25% duty-cycle, causing 2 times smaller DC-voltage drop after IF filtering. This allows for a 2 times increase in the impedance level of the IF filter, rendering more voltage gain for the same supply headroom. The implemented balun-LNA-I/Q-mixer topology achieves > 18 dB conversion gain, a flat noise figure < 5.5 dB from 500 MHz to 7 GHz, IIP2 = +20 dBm and IIP3 = -3 dBm. The core circuit consumes only 16 mW from a 1.2 V supply voltage and occupies less than 0.01 mm2 in 65 nm CMOS.

151 citations


Journal ArticleDOI
TL;DR: In this paper, a novel 90deg broadband balun comprising a broadband 90deg Schiffman phase shifter is introduced as a means of enhancing the wideband circular polarization performance of dual-fed type microstrip antennas.
Abstract: A novel 90deg broadband balun comprising a broadband 90deg Schiffman phase shifter is introduced as a means of enhancing the wideband circular polarization performance of dual-fed type microstrip antennas. The proposed 90deg broadband balun delivers good impedance matching, balanced power splitting and consistent 90deg (plusmn5deg) phase shifting, across a wide bandwidth (~57.5%). A circular patch antenna utilizing the proposed 90deg broadband balun is shown to attain measured impedance(S11< -10 dB) and axial ratio (AR < 3 dB) bandwidths of 60.24% and 37.7%, respectively, for the dual L-probe case; and 71.28% and 81.6% respectively, for the quadruple L-probe case.

139 citations


Journal ArticleDOI
TL;DR: The design and measurement results of millimeter-wave integrated circuits implemented in 65-nm baseline CMOS, including an on-chip spiral balun, and the transition from CPW to the balun and transistor noise parameter measurement results at V-band are presented.
Abstract: We present the design and measurement results of millimeter-wave integrated circuits implemented in 65-nm baseline CMOS. Both active and passive test structures were measured. In addition, we present the design of an on-chip spiral balun and the transition from CPW to the balun and report transistor noise parameter measurement results at V-band. Finally, the design and measurement results of two amplifiers and a balanced resistive mixer are presented. The 40-GHz amplifier exhibits 14.3 dB of gain and the 1-dB output compression point is at +6-dBm power level using a 1.2 V supply with a compact chip area of 0.286 mm2. The 60-GHz amplifier achieves a measured noise figure of 5.6 dB at 60 GHz. The AM/AM and AM/PM results show a saturated output power of +7 dBm using a 1.2 V supply. In downconversion, the balanced resistive mixer achieves 12.5 dB of conversion loss and +5 dBm of 1-dB input compression point. In upconversion, the measured conversion loss was 13.5 dB with -19 dBm of 1-dB output compression point.

134 citations


Journal ArticleDOI
TL;DR: In this paper, a novel three-port balanced-to-unbalanced (balun) bandpass filter with both functions of balun and bandpass filters is presented and carefully examined.
Abstract: Novel balanced-to-unbalanced (balun) bandpass filters are presented and carefully examined. By properly converting a symmetric four-port balanced-to-balanced bandpass filter to a three-port device, with two ports forming a balanced output and one port remaining unbalanced, a novel three-port balun bandpass filter with both functions of balun and bandpass filter may be realized. Specifically, a balun bandpass filter is implemented with its center frequency at 0.99 GHz and a 3-dB fractional bandwidth (Bomega) of 10.1%. The implemented balun bandpass filter presents an excellent in-band balance performance with common-mode rejection ratio (Rcm) better than 41 dB (the corresponding amplitude and phase imbalances are within 0.003deg and 1deg) over the pass- band. In this study, a wideband balun bandpass filter is also implemented so as to improve the wideband performance of the quasi- Yagi antenna. Being integrated with the proposed wideband balun bandpass filter, the implemented quasi-Yagi antenna achieves a bandwidth of 48% for IS11 | < -10 dB, with front-to-back ratio better than 13 dB, cross-polarization smaller than -20 dB, and peak gain of 3-5 dBi within the wide operating bandwidth.

87 citations


Journal ArticleDOI
TL;DR: Experiments for both balanced and unbalanced tag antenna measurement demonstrate the differential probe can provided better agreement with simulated results, as well as demonstrating the importance of accurate impedance measurement.
Abstract: This paper presents a method of antenna impedance measurement for RFID tag antenna based on a differential probe. The importance of accurate impedance measurement in optimal design of tag antenna, especially for the metal tags, is first addressed. Afterwards, an overview of the existing methods based on the single- ended probe and the balun probe is presented. The proposed method using the differential probe is explained based the well-known two port network model. Experiments for both balanced and unbalanced tag antenna measurement demonstrate the differential probe can provided better agreement with simulated results.

74 citations


Journal ArticleDOI
TL;DR: An integrated 2.4 GHz CMOS receiver front-end according to the IEEE 802.15.4 standard is presented, based on a 6 MHz low-IF topology, which uses an inductorless LNA and a new clocking scheme for driving a passive mixer.
Abstract: An integrated 2.4 GHz CMOS receiver front-end according to the IEEE 802.15.4 standard is presented in this paper. It integrates the overall RF part, from the balun up to the first stage of the channel filter, as well as the cells for the LO signal conditioning. The proposed architecture is based on a 6 MHz low-IF topology, which uses an inductorless LNA and a new clocking scheme for driving a passive mixer. When integrated in a 90 nm CMOS technology, the receiver front-end exhibits an area of only 0.07 mm2, or 0.23 mm2 when including an input integrated balun. The overall chip consumes 4 mA from a single 1.35 V supply voltage and it achieves a 35 dB conversion gain from input power in dBm to output voltage in dBvpk, a 7.5 dB NF value, -10 dBm of IIP3 and more than 32 dB of image rejection.

74 citations


Journal ArticleDOI
TL;DR: In this paper, the effects of the IC material properties and antenna geometry on radiation and impedance characteristics have been studied under the conditions under which standard digital bulk Si technology can yield efficient on-chip antennas and baluns for fully differential transmitter and receiver implementations.
Abstract: The conditions are investigated under which standard digital bulk Si technology can yield efficient on-chip antennas and baluns for fully differential transmitter and receiver implementations. The effects of the IC material properties and the antenna geometry on radiation and impedance characteristics have been studied. 24 GHz on-chip antennas on lossy Si have been successfully demonstrated, using a standard IC fabrication compatible Cu process. The fabricated antennas demonstrate a gain ranging from 8- to - 10.5 dBi, which is to the best of the author's knowledge, the highest gain reported for antennas in a 10 Omega-cm Si substrate to date.

73 citations


Journal ArticleDOI
TL;DR: In particular, insights in the design of a fully differential cascode topology for high efficiency and reliable operation are provided and a narrowband lumped element balun, employing minimum number of integrated inductors for minimum power loss, is introduced.
Abstract: Integration of the power amplifier together with signal processing in a transmitter is still missing in demanding RF commercial products. Issues preventing PA integration include LO pulling phenomena, thermal dissipation, and power efficiency. In this work we investigate high efficiency watt range Class-E PAs and integrated baluns. In particular, insights in the design of a fully differential cascode topology for high efficiency and reliable operation are provided and a narrowband lumped element balun, employing minimum number of integrated inductors for minimum power loss, is introduced. Two versions have been manufactured using a 0.13 mum CMOS technology. The first comprises the driver, and a differential PA connected to an external low-loss commercial balun. Experiments prove 31 dBm delivered output power, with 58% PAE and 67% drain efficiency, at 1.7 GHz. The second version adopts the same driver and PA and also integrates the balun. Experiments prove 30.5 dBm delivered output power, with 48% PAE and 55% drain efficiency, at 1.6 GHz.

68 citations


Journal ArticleDOI
TL;DR: In this article, an asymmetric broadside coupled Marchand balun with low-loss broadband characteristics for mixer designs is presented, and the correlation between balun impedance and a 3D multilayer CMOS structure is discussed and analyzed.
Abstract: This study presents an asymmetric broadside coupled balun with low-loss broadband characteristics for mixer designs. The correlation between balun impedance and a 3D multilayer CMOS structure are discussed and analyzed. Two asymmetric multilayer meander coupled lines are adopted to implement the baluns. Three balanced mixers that comprise three miniature asymmetric broadside coupled Marchand baluns are implemented to demonstrate the applicability to MOS technology. Both a single and dual balun occupy an area of only 0.06 mm2. The balun achieves a measured bandwidth of over 120%, an insertion loss of better than 4.1 dB (3 dB for an ideal balun) at the center frequency, an amplitude imbalance of less than 1 dB, and a phase imbalance of less than 5deg from 10 to 60 GHz. The first demonstrated circuit is a Ku-band mixer, which is implemented with a miniaturized balun to reduce the chip area by 80%. This 17-GHz mixer yields a conversion loss of better than 6.8 dB with a chip size of 0.24 mm2. The second circuit is a 15-60-GHz broadband single-balanced mixer, which achieves a conversion loss of better than 15 dB and occupies a chip area of 0.24 mm2. A three-conductor miniaturized dual balun is then developed for use in the third mixer. This star mixer incorporates two miniature dual baluns to achieve a conversion loss of better than 15 dB from 27 to 54 GHz, and occupies a chip area of 0.34 mm2.

62 citations


Journal ArticleDOI
TL;DR: In this article, three monolithic star mixers using a new miniature dual balun are proposed, two triple spiral transformer mixers and a trifilar transformer mixer, and they exhibit bandwidth over 25-45 GHz with local oscillator isolations better than 20 dB.
Abstract: In this paper, three monolithic star mixers using a new miniature dual balun are proposed. The first one is a double spiral transformer mixer, and the second one is a trifilar transformer mixer. Both of these are fabricated using a commercial GaAs pseudomorphic HEMT process. The third is a 3-D transformer mixer, which is fabricated using a commercial CMOS process. These mixers exhibit bandwidths over 25-45 GHz (57%) with local oscillator isolations better than 20 dB. These star mixers are smaller than (lambda/6timeslambda/6) for the mixer core area. Compared with traditional star mixers, these mixers demonstrate 80% size reduction, and achieve good performance with the smallest chip size among all star mixers using monolithic microwave integrated circuit processes.

Journal ArticleDOI
TL;DR: In this paper, a novel metamaterial broadband microstrip balun design is proposed, where the odd mode is allowed while the even mode is rejected, and a virtual ground is formed between the symmetric plane.
Abstract: A novel metamaterial broadband microstrip balun design is proposed. The broadband balun consists of a pair of identical metamaterial transmission lines. In the odd mode, a virtual ground is formed between the symmetric plane. The odd mode is allowed while the even mode is rejected. No vias are required to realize the shunt inductors of the metamaterial lines, and no power divider is used. Baluns with good performance can be achieved. In this letter, two baluns are fabricated and measured. For the balun with seven units, the output amplitude difference is less than 0.7 dB, and the differential phase is 181deg plusmn 3deg from 1.6 to 3.6 GHz, while the input return loss is greater than 10 dB.

Journal ArticleDOI
TL;DR: In this article, the authors have discussed various aspects of designing miniaturized LTCC LC filters for RF applications and demonstrated that by making use of the flexibility of LTCC technology, a compact LC bandpass filter can be realized for various RF applications.
Abstract: Over the past few years, a great amount of effort has been spent on LTCC filters or related research [21]?[28]. Some of these components have more advanced functionalities, such as a combination of filter and balun, or a complete front-end module with balun, filter, and matching network. At the same time, advanced methodologies have also been developed to design these components [29]. All the enjoyment of miniaturized RF components or modules is due to the promising three-dimensional design flexibility of LTCC technology. It is expected that a variety of functionally complex components will be continuously available on the market such that the cost and size of the overall wireless terminal can be further reduced. Various aspects of designing miniaturized LTCC LC filters have been briefly discussed here. Conventional coupled LC resonators are commonly used in LTCC filters for RF applications because of their compact size advantage. The shunted parallel resonator in this type of filter can be realized directly as a lumped-element or distributed quarter- wavelength stripline with or without loaded capacitors. Filters with distributed resonators in general have better passband insertion loss performance. Moreover, there are many ways to improve the rejection performance in an LTCC filter design; for example, by modifying the resonators or admittance inverters so as to introduce transmission zeros at the stopband. It was demonstrated, through a design example, that by making use of the flexibility of LTCC technology, a compact LC bandpass filter can be realized for various RF applications.

Journal ArticleDOI
TL;DR: In this paper, the design of a dual-band balun using tapped stubs and stepped-impedance structures is presented, where the two output signals of the balun are out-of-phase at the two operating frequencies.
Abstract: This letter presents the design of a dual-band balun using tapped stubs and stepped-impedance structures By adjusting the impedances of the tapped stubs properly, the two output signals of the balun are out-of-phase at the two operating frequencies which is essential for the balun operation Meanwhile, the stepped-impedance structure is designed to satisfy the dual-band matching condition at the input port Closed form design equations are derived using the even-odd mode method Based on these equations, a microstrip balun on Rogers' duroid/RT 5880 substrate operating at 245 GHz/525 GHz is designed, fabricated, and measured The measurement results verify the dual-band operations of the balun Finally, the impedance transformation property of the proposed dual-band balun is discussed

Journal ArticleDOI
TL;DR: In this work, the design and measurement of a new 4x subharmonic mixer circuit is presented using CMOS 0.18 m technology, which uses a modified Gilbert-cell topology with octet-phase LO switching transistors to perform the quadruple sub Harmonic mixing.
Abstract: In this work, the design and measurement of a new 4x subharmonic mixer circuit is presented using CMOS 0.18 m technology. With an RF input signal at 12.1 GHz, and an LO signal at 3.0 GHz, an intermediate frequency of 100 MHz is produced (fIF = fRF - 4fLO). The mixer uses a modified Gilbert-cell topology with octet-phase LO switching transistors to perform the quadruple subharmonic mixing. Included in the design is an active balun for the RF signal and a circuit that generates an octet-phase LO signals from a differential input. The mixer has a conversion gain of approximately 6 dB, 1-dB compression point of -12 dBm, IIP3 of -2 dBm, and IIP2 of 17 dBm. The circuit also exhibits excellent isolation between its ports (e.g. LO-RF: 71 dB, 4LO-RF: 59 dB).

Journal ArticleDOI
TL;DR: In this paper, a new configuration for an active balun, which uses a cascode and cascade pair with the shared input transistor, is proposed, which operates over a broad bandwidth up to 17 GHz where the imbalance of the differential output is less than 1.8 dB in amplitude and less then 10 in phase, over the input's dynamic range of -25-5 dBm, under the dc power consumption of 198.8 mW.
Abstract: A new configuration is proposed for an active balun, which uses a cascode and cascade pair with the shared input transistor. It is designed in the IBM 8HP 130-nm BiCMOS process, which operates over a broad bandwidth up to 17 GHz where the imbalance of the differential output is less than 1.8 dB in amplitude and less then 10 in phase, over the input's dynamic range of -25-5 dBm, under the dc power consumption of 198.8 mW. The circuit contains no internal dc blocking capacitors so that the bandwidth's lower end frequency best extends as close to dc as possible. The circuit contains only one line inductor with the value of 0.2 nH, and the compacted layout is expected to fit in limited chip areas as small as 0.2 mm times 0.2 mm, which makes them well suited for built-in self-test applications, as well as general differential circuits requiring compact-sized broadband baluns.

Journal ArticleDOI
TL;DR: In this article, a 1 : 8 differential power divider is implemented in a commercial SiGe BiCMOS process using fully shielded broadside-coupled striplines integrated vertically in the silicon interconnect stackup.
Abstract: This paper presents a 1 : 8 differential power divider implemented in a commercial SiGe BiCMOS process using fully shielded broadside-coupled striplines integrated vertically in the silicon interconnect stackup. The 1 : 8 power divider is only 1.12 x1.5 mm2 including pads, and shows 0.4-dB rms gain imbalance and <3deg rms phase imbalance from 40 to 50 GHz over all eight channels, a measured power gain of 14.9 plusmn0.6 dB versus a passive divider at 45 GHz, and a 3-dB bandwidth from 37 to 52 GHz. A detailed characterization of the shielded broadside-coupled striplines is presented and agrees well with simulations. These compact lines can be used for a variety of applications in SiGe/CMOS millimeter-wave circuits, including differential signal distribution, miniature power dividers, matching networks, filters, couplers, and baluns.

Journal ArticleDOI
TL;DR: In this paper, a new single-to-balanced multicoupled line bandpass filter structure is proposed, which is composed of a multicouple line of electric length much shorter than lambda/8 along with shunt capacitors loaded at suitable positions.
Abstract: This paper presents the design procedure and performance of a new single-to-balanced multicoupled line bandpass filter structure. The proposed filter is composed of a multicoupled line of electric length much shorter than lambda/8 along with shunt capacitors loaded at suitable positions. By a proper design of ground terminations for the multicoupled line, the proposed filter is simultaneously equipped with the functionality of a bandpass filter, a balun, and an impedance transformer. The bandpass characteristic can be easily developed to higher order for better selectivity. The graph-transformation method for coupled-line analysis is adopted to make the design procedure efficient and intuitive. To validate the design procedure and feasibility of proposed filter for mobile applications, two design examples with different filter order, impedance transformation ratio, fractional bandwidth and center frequency have been implemented in chip type by using the low temperature co-fired ceramic technology. The second-order design is realized in a chip size of 2012, while the third-order one is realized in a chip size of 2612. Moreover, an additional transmission zero in the upper stopband can be achieved and controlled flexibly by adjusting the outer printed circuit board layout with minimum effect on passband performance. Fabrication and measurement of these designs show that compact sizes and good agreements between measured and simulated results can be obtained, which demonstrate their suitability in modern mobile communication applications.

Patent
Adedayo Ojo1
14 Aug 2008
TL;DR: In this paper, a single-ended input low noise amplifier (LNA) with differential output is described, and a transition frequency and a matching network gain are tuned via configurable gate-source capacitors.
Abstract: Methods and systems for a single-ended input low noise amplifier (LNA) with differential output are disclosed and may include configuring the LNA and/or a balun on a chip for single-ended or differential mode, which may function as a load for the LNA. A frequency response and gain of the LNA may be configured via switched capacitors and resistors, which may include CMOS transistors. A transition frequency, and thus impedance matching and matching network gain, may be tuned via configurable gate-source capacitors. A received signal may be filtered via a surface acoustical wave (SAW) filter. The LNA may be impedance matched with an input device via the transition frequency tuning and off chip inductors and/or capacitors. The LNA may be configured for single-ended or differential input mode via switches outside of a signal path to the LNA and reverse isolation may be enabled via a cascode device.

Proceedings ArticleDOI
19 May 2008
TL;DR: In this paper, a post-CMOS compatible aluminum nitride (AlN) MEMS filters operating in the very (VHF) and ultra (UHF) high frequency bands are presented.
Abstract: This paper reports the development of narrow-bandwidth, post-CMOS compatible aluminum nitride (AlN) MEMS filters operating in the very (VHF) and ultra (UHF) high frequency bands. Percent bandwidths less than 0.1% are achieved utilizing a mechanically coupled filter architecture, where a quarter wavelength beam attached in low velocity coupling locations is used to connect two AlN ring resonators. The filter bandwidth has been successfully varied from 0.09% to 0.2% by moving the attachment of the coupling beam on the ring to locations with different velocity at resonance. Insertion losses of 11 dB are obtained for filters centered at 99.5 MHz with low termination impedances of 200 Omega. Utilizing a passive temperature compensation technique, the temperature coefficient of frequency (TCF) for these filters has been reduced from -21 ppm/C to 2.5 ppm/C. The reduced TCF is critical for narrow bandwidth filters, requiring only 13% of the filter bandwidth to account for military range (-55 to 125 C) temperature variations compared to 100% for uncompensated filters. Filters operating at 557 MHz are realized using overtone operation of the ring resonators and coupling beam where higher insertion losses of 32 dB into 50 Omega are seen due to the finite resonator quality factor and narrow bandwidth design. Overtone operation allows for the implementation of fully differential and balun type filters where the stop-band rejection is as high as 38 dB despite the increased insertion loss.

Journal ArticleDOI
TL;DR: In this paper, a 77 GHz IQ modulator in a fully differential circuit configuration is presented, which includes an LO buffer amplifier, a medium-power output stage, a double-balanced active mixer architecture and on-chip baluns for easy characterization.
Abstract: A 77-GHz IQ modulator in a fully differential circuit configuration is presented. It includes an local oscillation (LO) buffer amplifier, a medium-power output stage, a double-balanced active mixer architecture and on-chip baluns for easy characterization. A differential branch-line coupler provides quadrature phase signals at the upconversion mixer LO inputs. The circuit is manufactured in a 200-GHz transit frequency technology, and the circuit performance is shown by on-wafer measurements.

Journal ArticleDOI
TL;DR: In this paper, two types of wideband quasi-Yagi antennas are successfully designed and implemented in Ku- and Ka-band with frequency bandwidths of 53.2% and 29.1% respectively.
Abstract: In this study, a systematic and simplified design procedure for quasi-Yagi antennas is presented. The design is based on the simple field and impedance matching among antenna components. This new antenna design is possible due to the newly developed ultra-wideband balun. Two types of wideband quasi-Yagi antennas are successfully designed and implemented in Ku- and Ka-band with frequency bandwidths of 53.2% and 29.1%, respectively. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2068–2071, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23563

Journal ArticleDOI
TL;DR: In this article, a K-band sub-harmonically pumped resistive mixer with a miniature Marchand balun is demonstrated using standard 0.13 mum CMOS technology, which has a conversion loss of 11-12 dB at fIF = 100 MHz and PLO = 7 dBm for RF frequencies from 18 to 26 GHz.
Abstract: A K-band sub-harmonically pumped resistive mixer is demonstrated using standard 0.13 mum CMOS technology. A miniature Marchand Balun is integrated with the resistive mixer to generate equal amplitude and out-of-phase signals for mixer's local oscillation (LO) port directly on the lossy silicon substrate. The sub-harmonic resistive mixer with the integrated Marchand balun has conversion loss of 11-12 dB at fIF = 100 MHz and PLO = 7 dBm for RF frequencies from 18 to 26 GHz. The LO-RF and LO-IF isolations are approximately 30 and 33 dB, respectively.

Patent
14 Feb 2008
TL;DR: In this article, a balun transformer is provided, in which first to fourth layer coils are stacked and coupled magnetically; one end of each coil of the first to four layer coils is grounded; the second and third layer coil are connected in parallel, an unbalanced signal is input/output to/from a common terminal of the second-and third-layer coils; a first balanced signal is incoming/outgoing to/output from the other end of the fourth-layer coil.
Abstract: There is provided a balun transformer, in which first to fourth layer coils are stacked and coupled magnetically; one end of each coil of the first to fourth layer coils is grounded; the second and third layer coils are connected in parallel, an unbalanced signal is input/output to/from a common terminal of the second and third layer coils; a first balanced signal is input/output to/from the other end of the first layer coil; and a second balanced signal is input/output to/from the other end of the fourth layer coil.

Proceedings ArticleDOI
01 Oct 2008
TL;DR: A novel balanced-to-unbalanced (balun) diplexer that has the merits of compact size, wide stopbands, high isolation, and good common-mode rejection ratio is presented.
Abstract: In this work, a novel balanced-to-unbalanced (balun) diplexer is presented. By properly converting symmetric four-port balanced-to-balanced bandpass filter to a three-port device, a balun bandpass filter with high selectivity and extended stopband can be realized. Based on such a well-designed balun bandpass filter, a balun diplexer can be accomplished by combining two balun bandpass filter with two 50 matching lines. For demonstration, two fourth-order balun bandpass filters centered at 1.2 GHz and 1 GHz are employed to design and fabricate the balun diplexer. Specifically, the fabricated balun diplexer has the merits of compact size, wide stopbands, high isolation, and good common-mode rejection ratio.

Proceedings ArticleDOI
18 Nov 2008
TL;DR: A low-power CMOS RF front-end for 3-5 GHz non-coherent impulse-radio ultra-wideband (IR-UWB) receiver that achieves an input sensitivity of -91 dBm for UWB on-off keying (OOK) input signal and an energy efficiency of 3.1 nJ/bit.
Abstract: This paper presents a low-power CMOS RF front-end for 3-5 GHz non-coherent impulse-radio ultra-wideband (IR-UWB) receiver. The proposed front-end comprises a variable-gain low noise amplifier (VG-LNA), an active balun and an analog squarer. Current reuse topology has been adopted in both VG-LNA and active balun to reduce the power consumption. The squarer design is based on the quadratic law of MOSFET in saturation and the performance is optimized for 3-5 GHz UWB signal detection using cascode stage and active load. The VG-LNA has a measured maximum voltage gain of 33 dB/12 dB for high/low gain modes with minimum noise figure 3.7 dB/4.2 dB respectively. Measurements show that the proposed RF front-end achieves an input sensitivity of -91 dBm for UWB on-off keying (OOK) input signal at 1 Mbps pulse rate with an energy efficiency of 3.1 nJ/bit.

Journal ArticleDOI
TL;DR: A fully integrated WiMedia compliant UWB transceiver supporting band groups 1 to 6 (3.168 GHz to 10.560 GHz), implemented in 0.13 μm SiGe BiCMOS technology will be presented.
Abstract: A fully integrated WiMedia compliant UWB transceiver supporting band groups 1 to 6 (3.168 GHz to 10.560 GHz), implemented in 0.13 μm SiGe BiCMOS technology will be presented. The transceiver is packaged in a small 40 pin 5 mm × 5 mm micro lead frame (MLF) package and includes a broadband T/R switch, RF balun and all PLL loop filter components. The receiver has a NF of 4.5 dB to 5.8 dB and a dynamic range of more than 50 dB. The transmitter meets US and international transmit mask requirements.

Proceedings ArticleDOI
01 Feb 2008
TL;DR: The aim of the 2.4GHz front-end receiver presented in this paper is the minimization of both cost and energy consumption, focusing on WPAN IEEE 802.15.4 transceivers, and an area reduction by at least 70% is achieved.
Abstract: The aim of the 2.4GHz front-end receiver presented in this paper is the minimization of both cost and energy consumption, focusing on WPAN IEEE 802.15.4 transceivers. It includes the entire RF part, from the balun to the first stage of the channel filter, as well as the LO signal conditioning cells. The proposed architecture uses an unmatched inductorless LNA and a new clocking scheme on a standard passive mixer. Compared to previously reported IEEE 802.15.4 receivers, an area reduction by at least 70% is achieved. The power consumption is relatively low at 5.4mW with a state-of-the-art noise and linearity performance. The receiver front-end operates at 1.35V. It is implemented in a 90nm CMOS technology using two thick metals, and alucap with RFMOM capacitors.

Proceedings Article
19 May 2008
TL;DR: In this article, a novel design procedure for lumped element Marchand baluns is proposed and an analysis is performed on the balun structure in order to determine the conditions for ideal balun performance in terms of the lumped elements values.
Abstract: In this paper a novel design procedure for lumped element Marchand baluns is proposed. An analysis is performed on the balun structure in order to determine the conditions for ideal balun performance in terms of the lumped element values. The analysis is verified by two broadband designs centered around 22.75 GHz and differing only in terms of their impedance transformation ratio. EM simulation results on our proposed lumped element Marchand balun structure predicts an insertion loss of 4 dB and return loss of 40 dB at the design frequency of 22.75 GHz. The amplitude and phase imbalance is predicted to be better than 1 dB and 60, respectively obtained over a wide 15 GHz bandwidth.

Patent
04 Feb 2008
TL;DR: In this article, the reaction circuit component is tuned such that the harmonically suppressed balun transformer resonates at a selected harmonic of the fundamental frequency, which is the same as in this paper.
Abstract: An electronic assembly includes a substrate (66), a balun transformer (42) formed on the substrate (66) and including a first winding (50) and a second winding (52), each having respective first and second ends, and a reaction circuit component (48) formed on the substrate (66) and electrically coupled to the second winding (52) between the first and second ends thereof. The balun transformer (42) and the reaction circuit component (48) jointly form a harmonically suppressed balun transformer having a fundamental frequency, and the reaction circuit component (48) is tuned such that the harmonically suppressed balun transformer resonates at a selected harmonic of the fundamental frequency.