Ka-band monolithic GaAs balanced mixers

Monolithic integrated circuits have been developed on semi-insulating GaAs substrates for millimeter-wave balanced mixers. The GaAs chip is used as a suspended stripline in a cross-bar mixer circuit. A double sideband noise figure of 4.5 dB has been achieved with a monolithic GaAs balanced mixer filter chip over a 30- to 32-GHz frequency range. A monolithic GaAs balanced mixer chip has also been optimized and combined with a hybrid MIC IF preamplifier in a planar package with significant improvement in RF bandwidth and reduction in chip size. A double sideband noise figure of less than 6 dB has been achieved over a 31- to 39-GHz frequency range with a GaAs chip size of only 0.5 × 0.43 in. This includes the contribution of a 1.5-dB noise figure due to IF preamplifier (5-500 MHz).     

12-GHz-Band GaAs Dual-Gate MESFET Monolithic Mixers

12-GHz-band GaAs dual-gate MESFET monolithic mixers have been developed for use in direct broadcasting satellite receivers. In order to reduce chip size, a buffer amplifier has been connected directly after a mixer IF port, instead of employing an IF matching circuit. The mixer and the buffer were fabricated on separate chips, so that individual measurements could be achieved. Chip size is 0.96X 1.26 mm for the mixer and 0.96X0.60 mm for the buffer. A dual-gate FET for the mixer, as well as a single-gate FET for the buffer, has a closely spaced electrode structure. Gate length and width are 1 µm and 320 µm, respectively. The mixer with the buffer provides 2.9+-0.4-dB conversion gain with 12.3+-0.3dB SSB noise figure in the 11.7-12.2-GHz RF band. Local oscillator (LO) frequency is 10.8 GHz. A low-noise converter was constructed by connecting a monolithic preamplifier, an image rejection filter, and a monolithic IF amplifier to the mixer. The converter provides 46.8+-1.5-dB conversion gain with 2.8+-0.2-dB SSB noise figure in the same frequency band.     

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.     

A low-voltage 5.1-5.8-GHz image-reject receiver with wide dynamicrange

A monolithic 5-6-GHz band receiver, consisting of a differential preamplifier, dual doubly balanced mixers, cascaded injection-locked frequency doublers, and a quadrature local oscillator generator and prescaler, realizes over 45 dB of image-rejection in a mature 25-GHz silicon bipolar technology. The measured single sideband (50 Ω) noise figure is 5.1 dB with an IIP3 of -4.5 dBm and 17-dB conversion gain at 5.3 GHz. The 1.9×1.2 mm² IC is packaged in a standard 32-pin ceramic quad flatpack and consumes less than 50 mW from a 2.2-V supply     

A high-IP3 RF receiver chip set for mobile radio base stations upto 2 GHz

We present a monolithically integrated high third-order intercept point (IP3) radio frequency (RF) receiver chip set for mobile radio base stations up to 2 GHz, in a 25-GHz f_T Si bipolar production technology. The chip set consists of a RF preamplifier, active mixer circuits, and an intermediate frequency (IF) limiter. The preamplifier gain is 12 dB, the noise figure is 5.5 dB at 900 MHz, and the output (OIP3) is up to +24 dBm depending on supply voltage. The two different mixers provide a conversion gain of 1.5 dB up to 3 dB, an OIP3 in the range of +21 dBm up to +29 dBm, and a minimal single sideband (SSB) noise figure of 13 dB. The IF limiter shows an excellent limiting characteristic at 10 dBm output power and has a high bandwidth of more than 1 GHz     

A 31-GHz monolithic GaAs mixer/preamplifier circuit for receiver applications

The portion of a monolithic receiver containing integrated Schottky mixer diodes and MESFET'S with microstrip circuitry has been developed and tested at 31 GHz. This work is part of a program to establish the feasibility of monolithic receivers and transmitters at microwave and millimeter-wave frequencies. Receiver designs using high-cutoff frequency diodes in a mixer configuration followed by a MESFET amplifier are capable of operating from microwave through millimeter-wave frequencies. However, the fabrication of monolithic receiver designs requires the integration on the same wafer of devices with different material requirements. We have developed a compatible integration scheme which is fundamental to the fabrication of monolithic receivers at millimeter-wave frequencies. Fabrication and design considerations for the 31-GHz balanced mixer and IF preamplifier are described. Completed monolithic units typically exhibit a conversion gain of 4 dB from the signal frequency of 31 GHz to the IF frequency of 2 GHz. The associated noise figure is typically 11.5 dB.     

High-performance millimetre-wave mixer diodes fabricated using a deep mesa etch approach

Schottky-barrier junction mixer diodes compatible with monolithic integration have been fabricated on semi-insulating GaAs substrates using buried VPE n+ layers and deep mesa etch processing. A 590 GHz cutoff frequency was determined using modified DeLoach analysis and fin-line chip mounting. A 5.3 dB (SSB) noise figure and a 4.8 dB conversion loss were obtained at 35 GHz for a pair of chips in a balanced microstrip mixer.     

A low-current Ku-band GaAs monolithic image rejectiondown-converter

A single-chip image rejection downconverter has been designed, fabricated. and tested for broadcast satellite receivers operating in the 11.7- to 12.2-GHz range. The downconverter consists of an RF low-noise amplifier (LNA), a filter-type image rejection mixer (IRM), and an intermediate frequency amplifier (IFA). It receives 11.7- to 12.2-GHz RF signals and down converts to 1.0- to 1.5-GHz IF signals with an external local oscillator. Since the filter integrated on the downconverter produces an image rejection of more than 30 dB, the downconverter requires no off-chip circuits for the image rejection. A conversion gain of 37±1 dB and a noise figure of less than 3.5 dB have been achieved over the RF frequency range. The current dissipation is only 40 mA, and the chip size is 2.8 mm×2.8 mm×0.45 mm     

Airborne Imaging System Using a Cryogenic 90-Ghz Receiver

A cryogenic 90-GHz receiver has heen developed with a noise figure of 2.36 dB ((double sideband) (DSB)) and an instantaneous band-width of 1.2 GHz. The cooled front-end consists of a Schottky-barrier mixer followed by a GaAs FET IF amplifier. The radiometer is small in size and weighs only 52 kg, including the refrigerator system. It is part of an airborne imaging system, that has been fight-tested aboard a Dornier Do 28 aircraft. First test results are presented.     

X-Band Integrated Circuit Mixer with Reactively Terminated Image

An X-band mixer using GaAs Schottky barrier diodes with a thin-film 500-MHz IF preamplifier was developed using hybrid microwave integrated circuit techniques. The balanced mixer had filters to provide a short circuit at the image frequency. The entire mixer preamplifier occupied an area of only 0.38 square inches and had a noise figure of 6.7 dB which corresponded quite closely to the theoretical noise figure considering all losses. The thin-film IF amplifier alone had a 2.2-dB noise figure and the mixer IF amplifier coupling network had a loss of 0.4 dB.     

X-Band Integrated Circuit Mixer with Reactively Terminated Image

An X-band mixer using GaAs Schottky barrier diodes with a thin-film 500-MHz IF preamplifier was developed using hybrid microwave integrated circuit techniques. The balanced mixer had filters to provide a short circuit at the image frequency. The entire mixer preamplifier occupied an area of only 0.38 square inches and had a noise figure of 6.7 dB which corresponded quite closely to the theoretical noise figure considering all losses. The thin-film IF amplifier alone had a 2.2-dB noise figure and the mixer IF amplifier coupling network had a loss of 0.4 dB.     

A Compact 60-GHz Transmitter--Receiver

A new, compact, low-cost, and reliable 60-GHz transmitier-receiver was developed for civilian use. Common components are used for transmitting and receiving functions. An IMPATT oscillator generates the millimeter-wave output power for both the transmitter and the receiver local oscillator. A common antenna is also used for transmitting and receiving signals without a circulator. A mixer is used as a modulator in transmission as well as a receiver front end. A noise figure of 13 dB is obtained by a balanced mixer with a 200-MHz IF frequency differential preamplifier. A reliable packaged GaAs varactor diode is used for the mixer-modulator (MM).     

GaAs Monolithic MIC's for Direct Broadcast Satellite Receivers

A 12-GHz low-noise amplifier (LNA), a 1-GHz IF amplifier (IFA), and an 11-GHz dielectric resonator oscillator (DRO) have been developed for DBS home receiver applications by using GaAs monolithic microwave integrated circuit (MMIC) technology. Each MMIC chip contains FET's as active elements and self-biasing source resistors and bypass capacitors for a single power supply operation. It also contairns dc-block and RF-bypass capacitors. The three-stage LNA exhibits a 3.4-dB noise figure and a 19.5-dB gain over 11.7-12.2 GHz. The negative-feedback-type three-stage IFA shows a 3.9-dB noise figure and a 23-dB gain over 0.5-1.5 GHz. The DRO gives 10.mW output power at 10.67 GHz, with a frequency stability of 1.5 MHz over a temperature range from -40-80°C. A direct broadcast satellite (DBS) receiver incorporating these MMIC's exhibits an overafl noise figure of /spl les/ 4.0 dB for frequencies from 11.7-12.2 GHz.     

2-20-GHz GaAs Traveling-Wave Amplifier

Single-stage and two-stage GaAs traveling-wave amplifiers operating with flat gain responses in the 2-20-GHz frequency range are described. The circuits are realized in monolithic form on a 0.1-mm GaAs substrate with 50-Omega input and output lines. Complete gate and drain dc bias circuitry is included on the chip. By cascading these amplifier chips, a 30-dB gain in the 2-20-GHz range is demonstrated, with 9+-1dB noise figure.     

A low-voltage 5.1-5.8-GHz image-reject downconverter RF IC

This paper describes a single-chip implementation of a low-voltage image-reject downconverter for a 5.1-5.8-GHz radio receiver. It consists of a low-noise preamplifier (LNA) that is simultaneously noise and power matched to the RF source, and dual doubly balanced mixers coupled to the LNA by a monolithic trifilar transformer. The image-reject architecture eliminates an RF filter, thereby simplifying packaging requirements. The downconverter realizes over 36 dB of image rejection while dissipating 24 mW from a 0.9 V supply, or 18.5 mW at 1.8 V. Conversion gain is 14 dB, IIP3=-5.5 dBm, and noise figure is 6.8 dB (single sideband 50 Ω) when operating from a 0.9 V supply     

2.5-THz GaAs monolithic membrane-diode mixer

A novel GaAs monolithic membrane-diode (MOMED) structure has been developed and implemented as a 2.5-THz Schottky diode mixer. The mixer blends conventional machined metallic waveguide with micromachined monolithic GaAs circuitry to form, for the first time, a robust, easily fabricated, and assembled room-temperature planar diode receiver at frequencies above 2 THz. Measurements of receiver performance, in air, yield at T_receiver of 16500-K double sideband (DSB) at 8.4-GHz intermediate frequency (IF) using a 150-K commercial Miteq amplifier. The receiver conversion loss (diplexer through IF amplifier input) measures 16.9 dB in air, yielding a derived “front-end” noise temperature below 9000-K DSB at 2514 GHz. Using a CO₂-pumped methanol far-infrared laser as a local oscillator at 2522 GHz, injected via a Martin-Puplett diplexer, the required power is ≈5 mW for optimum pumping and can be reduced to less than 3 mW with a 15% increase in receiver noise. Although demonstrated as a simple submillimeter-wave mixer, the all-GaAs membrane structure that has been developed is suited to a wide variety of low-loss high-frequency radio-frequency circuits     

A single-chip image rejecting receiver for the 2.44 GHz band usingcommercial GaAs-MESFET-technology

A single-chip receiver for the 2.44 GHz band has been designed. To minimize the number of chip connections as well as external components, an image rejecting architecture has been chosen. A two-stage voltage controlled ring oscillator is used as a quadrature LO-source. The IF phase relationship is achieved with RC allpass circuits. Special attention is paid to keep the design insensitive to process variations. The 3-mm² chip has been fabricated with commercial 1-μm E/D GaAs MESFET technology and comprises an RF preamplifier, a voltage controlled ring oscillator, a phasing type image reject mixer, an IF preamplifier and a prescaler (division by 16). Except for the power supply and the frequency tuning voltage, no external components are required for basic operation. Prototype devices from two wafer runs were investigated. Power consumption from a single supply voltage of 5 V is 0.6 W. An image rejection of 34 dB is measured over a 130 to 280 MHz IF bandwidth. With a simple input symmetrizing and matching network, a conversion gain of 34 dB and a noise figure of 6.5 dB are achieved. The short term frequency instability of the free running ring oscillator is 400 kHz. With simple passive analog phase lock circuitry, an SSB phase noise of -74 dBc/Hz at 100 kHz offset is attained     

A 1.9-GHz silicon receiver with monolithic image filtering

A 1.9-GHz fully monolithic silicon superheterodyne receiver front-end is presented; it consists of a low noise amplifier (LNA), a tunable image reject filter, and a Gilbert cell mixer integrated in one die. The receiver was designed to operate with a 1.9-GHz RF and a 2.2-GHz local oscillator (LO) for a 300-MHz IF. Two chip versions were fabricated on two different fabrication runs using a 0.5-μm bipolar technology with 25 GHz transit frequency (f_T). Measured performance for the receiver front-end version 1, packaged and without input matching, was: conversion gain 33.5 dB, noise figure 4.9 dB, input IP3 -28 dBm, image rejection 53 dB (tuned to reject a 2.5-GHz image frequency), and 15.9 mA current consumption at +3 V. The image rejection was tunable from 2.4-2.63 GHz by means of an on-chip varactor. Version 2 had increased mixer degeneration for improved linearity. Its measured performance for the packaged receiver with its input matched to 50 Ω was: conversion gain 24 dB, noise figure 4.8 dB, input IP3 -19 dBm, and 65 dB image rejection for a 2.5-GHz image with an image tuning range from 2.34-2.55 GHz     

A 170 MHz RF front-end for ERMES pager applications

A 170 MHz RF front-end for ERMES pager applications has been implemented in a 1.2 μm BiCMOS technology. The chip comprises a low noise amplifier with AGC, a double balanced mixer, a varactor tuned LC local oscillator, and an IF strip containing an AGC amplifier and a double balanced mixer with integrated active output filter. The LNA has a measured gain of 22.3 dB at 170 MHz with a usable AGC range of approximately 20 dB while the conversion transconductance of the mixer is 130 μS. This front-end is suitable for direct conversion and superheterodyne pager receivers, and its noise figure is 6.2 dB. Low power operation has been achieved with the front-end drawing 230 μA at 3 V, which is compatible with the intended application in wrist-watch style pagers     

A plastic package GaAs MESFET 5.8-GHz receiver front-end withon-chip matching for ETC system

A plastic package GaAs MESFET receiver front-end monolithic microwave integrated circuit operating at 5.8 GHz is presented in this paper. It has a two-stage low-noise amplifier followed by a dual-gate mixer. Operating at 3 V and 8.3 mA, a conversion gain of 20.4 dB, noise figure of 4.1 dB, and high port-to-port isolations have been achieved. Total chip size of 1.0×0.9 mm² has been achieved through on-chip matching for both RF and local-oscillator ports and the use of simple two-element matching networks for all interstage matching. The 3-dB bandwidth of conversion gain is 1 GHz