A Novel 94-GHz MHMET-Based Diode Mixer Using a 3–dB Tandem Coupler

We report a high-performance 94-GHz monolithic millimeter-wave integrated-circuit diode mixer using metamorphic high-electron mobility transistor (MHEMT) diodes and a coplanar waveguide tandem coupler. A novel single-balanced structure of diode mixer is proposed in this paper, where a 3-dB tandem coupler with two sections of parallel-coupled line and air-bridge crossover structures are used for wide frequency operation. The fabricated mixer exhibits excellent local oscillator–radio-frequency (LO–RF) isolation, greater than 30 dB, in the 5-GHz bandwidth of 91–96 GHz. A good conversion loss of 7.4 dB is measured at 94 GHz. The proposed MHEMT-based diode mixer shows superior LO–RF isolation and conversion loss to those of the W-band mixers reported to date.      

High-performance 94-GHz single balanced mixer using 70-nm MHEMTs and surface micromachined technology

We reported 94-GHz, low conversion loss, and high isolation single balanced active gate mixer based on 70-nm gate length InGaAs/InAlAs metamorphic high-electron mobility transistors (MHEMTs). This mixer showed that the conversion loss and isolation characteristics were 2.5/spl sim/3.5 dB and under -29 dB in the range of 92.95/spl sim/94.5 GHz, respectively. The low conversion loss of the mixer is mainly attributed to the high-performance of the MHEMTs exhibiting a maximum drain current density of 607 mA/mm, an extrinsic transconductance of 1015 mS/mm, a current gain cutoff frequency (f/sub t/) of 330 GHz, and a maximum oscillation frequency (f/sub max/) of 425 GHz. High isolation characteristics are due to hybrid ring coupler which adopted dielectric-supported air-gapped microstrip line structure using surface micromachined technology. To our knowledge, these results are the best performance demonstrated from 94 GHz single balanced mixer utilizing GaAs-based HEMTs in terms of conversion loss as well as isolation characteristics.     

High-Performance 94-GHz Single-Balanced Diode Mixer Using Disk-Shaped GaAs Schottky Diodes

We present a high-performance 94-GHz single-balanced monolithic millimeter-wave integrated-circuit (MMIC) mixer using the disk-shaped GaAs Schottky diodes grown on an n/$hbox{n}+$ epitaxial structure. Due to the superior characteristics of the GaAs diodes with high diode-to-diode uniformity, the mixer shows a conversion loss of 5.5 dB at 94 GHz, a 1-dB compression point $(P_{1 hbox{-}{rm dB}})$ of 5 dBm, and high local-oscillator to radio-frequency isolation above 30 dB in an RF frequency range of 91–97 GHz. To our knowledge, the fabricated mixer shows the best performance in terms of conversion loss at 94 GHz and $P_{1 hbox{-}{rm dB}}$ among the W-band MMIC mixers without amplifier circuits.      

A Novel Reduced-Size Rat-Race Broadside Coupler and Its Application for CMOS Distributed Sub-Harmonic Mixer

A broadband distributed sub-harmonic resistive field effect transistor mixer with a novel modified rat-race broadside coupler using a 0.13-mum CMOS foundry process is presented in this letter. Using the broadside coupler, a reduced-size rat-race is fabricated with a compact size of 110 times 80 mum². From the measurement results, the mixer achieved a conversion loss of 12 dB from 32 to 70 GHz of RF frequency. The passive sub-harmonic mixer has zero power consumption. With the modified rat-race broadside coupler, the mixer achieves a good LO-IF isolation of better than 30 dB and a compact core chip size of 0.55 times 0.4 mm².     

A high-performance W-band uniplanar subharmonic mixer

A uniplanar subharmonic mixer has been implemented in coplanar waveguide (CPW) technology. The circuit is designed to operate at RF frequencies of 92-96 GHz, IF frequencies of 2-4 GHz, and LO frequencies of 45-46 GHz. Total circuit size excluding probe pads and transitions is less than 0.8 mm ×1.5 mm. The measured minimum single-sideband (SSB) conversion loss is 7.0 dB at an RF of 94 GHz, and represents state-of-the-art performance for a planar W-band subharmonic mixer. The mixer is broad-band with a SSB conversion loss of less than 10 dB over the 83-97-GHz measurement band. The measured LO-RF isolation is better than -40 dB for LO frequencies of 45-46 GHz. The double-sideband (DSB) noise temperature measured using the Y-factor method is 725 K at an LO frequency of 45.5 GHz and an IF frequency of 1.4 GHz. The measured data agrees well with the predicted performance using harmonic-balance analysis (HBA). Potential applications are millimeter-wave receivers for smart munition seekers and automotive-collision-avoidance radars     

20-GHz 5-dB-gain analog multipliers with AlGaAs/GaAs HBTs

From-DC-to-above-20-GHz monolithic Gilbert cell analog multipliers have been developed using AlGaAs/GaAs HBT technology. As a double balanced active mixer, it exhibits very high conversion gain of above +5 dB with extremely high LO-IF isolation of 33 dB for RF/LO inputs up to 20 GHz. It exhibits conversion gain of +9 dB for 5 GHz RF/LO inputs. As a double balanced upconverter, it exhibits positive conversion gain with high LO-RF isolation of 23 dB for RF output up to 8.5 GHz. As a detection mixer in coherent optical heterodyne receivers, it can operate for RF/LO inputs up to 15 GHz under a less than -7.5 dBm LO input condition     

Compact 28-GHz subharmonically pumped resistive mixer MMIC using a lumped-element high-pass/band-pass balun

This work reports a novel lump-element balun for use in a miniature monolithic subharmonically pumped resistive mixer (SPRM) microwave monolithic integrated circuit. The proposed balun is simply analogous to the traditional Marchand balun. The coupled transmission lines are replaced by lump elements, significantly reducing the size of the balun. This balun requires no complicated three-dimensional electromagnetic simulations, multilayers or suspended substrate techniques; therefore, the design parameters are easily calculated. A 2.4-GHz balun is demonstrated using printed circuit board technology. The measurements show that the outputs of balun with high-pass and band-pass responses, a 1-dB gain balance, and a 5/spl deg/ phase balance from 1.7 to 2.45 GHz. The balun was then applied in the design of a 28-GHz monolithic SPRM. The measured conversion loss of the mixer was less than 11dB at a radio frequency (RF) bandwidth of 27.5-28.5 GHz at a fixed 1 GHz IF, a local oscillator (LO)-RF isolation of over 35 dB, and a 1-dB compression point higher than 9 dBm. The chip area of the mixer is less than 2.0 mm/sup 2/.     

X波段低变频损耗混频器设计

采用商用肖特基势垒二极管HSMS-2822,研制了低变频损耗、高隔离度X波段单平衡混频器。为实现所需要的混频带宽,本振信号和射频信号采用三分支定向耦合器耦合输入,仿真研究表明其能有效地改善工作频率带宽,提高本振端口与射频端口间的隔离度。通过设计合理的空闲频率回收电路,回收利用空闲频率能量,能有效地降低混频器变频损耗,提高本振信号、射频信号及空闲频率信号到中频端口的隔离度。在10.6GHz,测得最小变频损耗5.67dB;在10～11.5GHz,混频器变频损耗为6.4±0.7dB,变频损耗平坦度好,RF-IF隔离度优于27dB,LO-IF隔离度高于24dB,LO-RF隔离度优于14dB。     

94-GHz Beam-Lead Balanced Mixer

Using a newly developed GaAs beam-lead diode, we have developed and evaluated a balanced mixer at 94 GHz. The various components of the mixer were separately optimized using carefully designed low-frequency model studies as our primary design aid. These studies included the determination of guide impedance and guide wavelength for suspended stripline, and optimization of a waveguide to suspended stripline transition, low-pass filters, and diode location. This 94-GHz mixer exhibits an average single sideband (SSB) conversion loss of 6.2 dB over a 6-GHz RF bandwidth. Together with a bipolar IF amplifier, the system exhibits a 4.5-5.1-dB double sideband (DSB) noise figure over a 50-700-MHz IF bandpass. LO-to-RF isolation was greater that 27 dB over this range of operating frequencies. Finally, severe environmental test were successfully performed on the mixer between sucessive electrical characterization.     

带有小型化Balun的C波段单片GaAs pHEMT单平衡电阻性混频器

 本文介绍了一种带有小型化无源Balun的C波段单片GaAs pHEMT单平衡电阻性混频器.Balun 采用集总—分布式结构,使其长度与常用λ/4耦合线Balun相比缩小了11倍,大大降低了将无源Balun应用于C波段单片集成电路中所需的芯片尺寸.混频器采用单平衡电阻性结构,在零功耗的情况下实现了良好的线性和口间隔离性能.测试结果显示,在固定中频160MHz,本振输入功率0dBm条件下,在3.5~5GHz RF频带内,最小变频损耗为8.3dB,1dB压缩点功率为8.0dBm,LO至IF之间的隔离度为38dB.     

Design and fabrication of 94 GHz MMIC single balanced resistive mixer without IF balun

In this paper, a 94 GHz microwave monolithic integrated circuit (MMIC) single balanced resistive mixer affording high LO-to-RF isolation was designed without an IF balun. The single balanced resistive mixer, which does not require an external IF balun, was designed using a 0.1 μm InGaAs/InAlAs/GaAs metamorphic high electron mobility transistor (HEMT). The designed MMIC single balanced resistive mixer was fabricated using the 0.1 μm MHEMT MMIC process. From the measurement, conversion loss of the single balanced resistive mixer was 14.7 dB at an LO power of 10 dBm. The P_1 dB (1 dB compression point) values of the input and output were 10 dBm and −5.3 dBm, respectively. The LO-to-RF isolation of the single balanced resistive mixer was −35.2 dB at 94.03 GHz. The single balanced resistive mixer in this work provided high LO-to-RF isolation without an IF balun.     

A 90–96 GHz CMOS down-conversion mixer with high conversion gain and excellent LO–RF isolation

A 90–96 GHz down-conversion mixer for 94 GHz image radar sensors using standard 90 nm CMOS technology is reported. RF negative resistance compensation technique, i.e. NMOS LC-oscillator-based RF transconductance (GM) stage load, is used to increase the output impedance and suppress the feedback capacitance C_gd of RF GM stage. Hence, conversion gain (CG), noise figure (NF) and LO–RF isolation of the mixer can be enhanced. The mixer consumes 15 mW and achieves excellent RF-port input reflection coefficient of ?10 to ?36.4 dB for frequencies of 85–105 GHz. The corresponding -10 dB input matching bandwidth is 20 GHz. In addition, for frequencies of 90–96 GHz, the mixer achieves CG of 6.3–9 dB (the corresponding 3-dB CG bandwidth is greater than 6 GHz) and LO–RF isolation of 40–45.1 dB, one of the best CG and LO–RF isolation results ever reported for a down-conversion mixer with operation frequency around 94 GHz. Furthermore, the mixer achieves an excellent input third-order intercept point of 1 dBm at 94 GHz. These results demonstrate the proposed down-conversion mixer architecture is very promising for 94 GHz image radar sensors.     

Design and Performance of W-Band Broad-Band Integrated Circuit Mixers

Broad-band integrated circuit mixers rising a crossbar suspended stripline configuration and a finline configuration were developed with GaAs beamlead diodes. For the crossbar suspended stripline balanced mixer, less than 7.5-dB conversion loss for 15-GHz instantaneous, IF bandwidth was achieved with the LO at 75 GHz and the RF swept from 76 to 91 GHz. With the LO at 90 GHz, a conversion loss of less than 7.8 dB was achieved over a 14-GHz instantaneous bandwidth as the RF is swept from 92 to 105 GHz. For the finline balanced mixer, a conversion loss of 8 to 12 dB over a 32-GHz instantaneous IF bandwidth was achieved as the RF is swept from 76 to 108 GHz. Integrated circuit building blocks, such as filters, broadside couplers, matching circuits, and varions transitions, were also developed.     

A Miniaturized Monolithic 18–40 GHz Sub-harmonic Mixer

In this paper, a miniaturized 18–40 GHz sub-harmonic mixer is designed and implemented with 0.15 μm GaAs pHEMT process. The proposed mixer employs anti-parallel diode pair with parallel to ground configuration, and a novel coupler structure to feed RF and LO signals, resulting in broadband performance and compact chip size. The measured conversion loss is 10.3–13.5 dB in a wide operation frequency band of 18–40 GHz. The chip size is 0.66 mm².     

Low conversion-loss fourth subharmonic mixers incorporating CMRC for millimeter-wave applications

Low conversion-loss millimeter-wave fourth subharmonic (SH) mixer designs are proposed in this paper. A millimeter-wave (35 GHz) fourth SH mixer with four open/shorted stubs is designed and measured. The conversion loss is less than 15 dB within a 2.4-GHz bandwidth. The minimum loss is 11.5 dB at the center frequency. By replacing two of the shunt stubs with a dual-frequency in-line stub consisting of newly developed compact microstrip resonating cells (CMRCs), the performance of the SH mixer is improved significantly. At 35 GHz, the conversion loss of this new fourth SH mixer is as low as 6.1 dB with a 3-dB bandwidth of 6 GHz. The conversion loss in the whole Ka-band (26.5-40 GHz) is less than 16 dB. The proposed fourth SH mixer incorporating with CMRCs provides a low-cost high-performance solution for RF subsystem design.     

GaAs MMIC宽带双平衡混频器的研制

采用GaAs肖特基二极管工艺,设计并制造了一款宽带无源双平衡混频器,射频、本振频率为1.5～3.7 GHz,变频损耗小于10 dB,本振到射频隔离度大于35 dB,中频带宽DC～0.8 GHz.该混频器采用了环形二极管和螺旋式巴伦结构,在获得良好的变频损耗与隔离度的同时,显著减小了芯片面积,整体芯片尺寸为1.2 mm × 1.2 mm.     

The Design of Low LO-Power 60-GHz CMOS Quadrature-Balanced Self-Switching Current-Mode Mixer

This letter describes the analysis and measurement of a complementary metal-oxide semiconductor (CMOS) quadrature-balanced current-mode mixer with a 90^deg branch-line hybrid coupler and self-switching current-mode devices. The proposed mixer, using 0.13 mum 1P8M CMOS technology, can downconvert a 60 GHz RF signal to a 2 GHz intermediate frequency (IF) signal, with a local-oscillator power of 0 dBm at 58 GHz. In the design, the mixer had a single-end conversion gain of 1 dB and an input-referred 1 dB compression point of 2 dBm. The LO-RF isolation of the mixer can achieve -37 dB while using 3 mA from a supply voltage of 1.2 V.     

Design and implementation of a 94 GHz CMOS down-conversion mixer with integrated miniature planar baluns for image radar sensors

A 94 GHz down-conversion mixer for image radar sensors using standard 90 nm CMOS technology is reported. The down-conversion mixer comprises a double-balanced Gilbert cell with peaking inductors between RF transconductance stage and LO switching transistors for conversion gain (CG) enhancement and noise figure suppression, a miniature planar balun for converting the single RF input signals to differential signals, another miniature planar balun for converting the single LO input signals to differential signals, and an IF amplifier. The mixer consumes 22.5 mW and achieves excellent RF-port input reflection coefficient of ?10 to ?35.9 dB for frequencies of 87.6–104.4 GHz, and LO-port input reflection coefficient of ?10 to ?31.9 dB for frequencies of 88.2–110 GHz. In addition, the mixer achieves CG of 4.9–7.9 dB for frequencies of 81.8–105.8 GHz (the corresponding 3-dB CG bandwidth is 24 GHz) and LO–RF isolation of 37.7–47.5 dB for frequencies of 80–110 GHz, one of the best CG and LO–RF isolation results ever reported for a down-conversion mixer with operation frequency around 94 GHz. Furthermore, the mixer achieves an excellent input third-order intercept point of ?3 dBm at 94 GHz. These results demonstrate the proposed down-conversion mixer architecture is promising for 94 GHz image radar sensors.     

A subharmonic self-oscillating mixer with integrated antenna for60-GHz wireless applications

A balanced integrated-antenna self-oscillating mixer at 60 GHz is presented in this paper. The modal radiation characteristics of a dual-feed planar quasi-Yagi antenna are used to achieve RF-local oscillator (RF-LO) isolation between closely spaced frequencies. The balanced mixer is symmetric, inherently broad band, and does not need an RF balun. Pseudomorphic high electron-mobility transistors are used in a 30-GHz push-pull circuit to generate the second harmonic and a 30-GHz dielectric resonator was used to stabilize the fundamental oscillation frequency. This allows the possibility of building a balanced low-cost self-contained antenna integrated receiver with low LO leakage for short-range narrow-band communication. Phase locking can be done with half of the RF frequency. The circuit exhibits a conversion loss less than 15 dB from 60 to 61.5 GHz, radiation leakage of -26 dBm at 60 GHz, and IF phase noise of -95 dBc/Hz at 100-kHz offset     

High switching performance 0.1-/spl mu/m metamorphic HEMTs for low conversion loss 94-GHz resistive mixers

We report high switching performance of 0.1-/spl mu/m metamorphic high-electron mobility transistors (HEMTs) for microwave/millimeter-wave monolithic integrated circuit (MMIC) resistive mixer applications. Very low source/drain resistances and gate capacitances, which are 56 and 31% lower than those of conventional pseudomorphic HEMTs, are due to the optimized epitaxial and device structure. Based on these high-performance metamorphic HEMTs, a 94-GHz MMIC resistive mixer was designed and fabricated, and a very low conversion loss of 8.2 dB at a local oscillator power of 7 dBm was obtained. This is the best performing W-band resistive field-effect transistor mixer in terms of conversion loss utilizing GaAs-based HEMTs reported to date.