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The development of monolithic millimeter-wave Schottky diode mixers based on technological parameters is described. The complete equivalent circuit of the monolithic Schottky diode is calculated taking into account the semiconductor layer structure and the device geometry. This model has been used in a harmonic balanced software for designing monolithic single balanced mixers. In V-band a minimum DSB noise figure of 3.3 dB and a minimum conversion loss of 6 dB have been achieved. In W-band a minimum DSB noise figure of 4 dB and a minimum conversion loss of 7 dB have been obtained. >

A method of simultaneously fabricating MESFETs with a maximum frequency of oscillation (f/sub max/) of 70 GHz and Schottky diodes with a gain-bandwidth product (f/sub T/) of approximately=2300 GHz to produce a 60-GHz mixer is given. A deep selective n/sup +/ implantation for a buried n/sup +/ zone under the mixer diode was used. Metalorganic chemical vapor deposition (MOCVD) was used for the growth of the active n layer and an n/sup +/ surface contact layer. The MESFETs and the diodes were both fabricated with a recessed Schottky contact structure using Ti-Pt-Au metallization. Arrays of 30 different diodes and 55 different MESFETs were fabricated to study the process technology and to get optimum devices for a receiver chip containing a diode balanced mixer plus a low-noise intermediate-frequency (IF) amplifier. The conversion loss and noise figures of the diodes were measured and compared with those obtained from computer simulations. Both large- and small-signal analysis are included. The 60-GHz balanced mixer chip shows a conversion loss of 6.0 dB and a double-sideband noise figure of 3.3 dB. >

A fully monolithic GaAs-94 GHz downconverter consisting of a single balanced diode mixer and a two-stage IF amplifier has been fabricated in a MESFET technology on a single chip. A conversion gain of 14.5 dB combined with a double-sideband noise figure of 6.5 dB has been achieved at 94 GHz. The reported results have been obtained in a one-pass design and show the validity of the design method, using technology based Schottky diode equivalent circuit and harmonic balanced analysis, and they also prove the maturity of the technology for millimeter-wave applications. >

The design, fabrication, and evaluation of a monolithic 29-GHz dielectrically stabilized voltage-controlled oscillator (DVO) using a MESFET as the active device are described. The novel design yields an oscillator with excellent phase noise behavior and frequency tuning capabilities. A phase noise N/C/sub FM/ of -100 dBc/Hz at 100 kHz off carrier and an output power of+8 dBm without significant deviation over the full tuning range of 45 MHz are obtained. A frequency stability of -6 ppm/ degrees C is measured in the -20 degrees C to +80 degrees C temperature range for a+3 ppm/ degrees C temperature coefficient of the dielectric resonator. The MMIC (monolithic microwave integrated circuit) device is realized using a 0.25- mu m MESFET technology. >

The contribution describes the topology of the heterodyne 89 GHz channel of the Multifrequency Imaging Microwave Radiometer (MIMR). Several components such as double sideband 89 GHz mixer, 44.5 GHz local oscillator, frequency doubler, and IF low noise amplifier are realized using monolithic millimeter- and microwave technology. Detector and band-defining low-pass filter are lumped element assemblies. The frontend concept yields a compact low power consuming module with a proposed overall noise figure of about 5.5 dB. A gain of 52 dB is expected between the 89.1 GHz/spl plusmn/2.7 GHz RF input and the 0.1 GHz-2.7 GHz IF output.

We report on the design, fabrication and evaluation of 77 GHz monolithically integrated MMIC switches. Single-pole double-throw (SPDT) and single-pole three-throw (SP3T) switches were realized with Schottky diodes in a 0.25 /spl mu/m GaAs MESFET technology. To our knowledge, this is the first fabrication of Schottky diodes as switching elements at W-band. In a silicon SIMMWIC technology SPDT switches were developed with PIN diodes. Insertion losses of 1.5-2.5 dB and isolations better than 20 dB were obtained at 77 GHz for the different switch types. A comparison between the GaAs MESFET and the SIMMWIC technology concerning switch RF-performance, power capability and switching speed is given in this paper. >

A number of civil applications such as motion sensors and communications systems are planned to use the Ka-band frequency range. An MMIC chip set for the realization of the millimeter-wave front-end has been developed. The key MMIC circuit functions for Ka-band communication systems have been fabricated. Low noise amplifiers, a medium power amplifier, mixers and a dielectric resonator oscillator (DRO) have been developed using a common 0.25 /spl mu/m PMHFET technology allowing the future integration of several key components on a single chip. A voltage controlled oscillator has been realized in a GaInP-GaAs HBT technology for improvement of the phase noise performance. Low noise Schottky diode upconverter and downconverter are also available in 0.25 /spl mu/m MESFET technology with buried n/sup +/ layer.

A multipurpose MMIC gate mixer has been designed, fabricated and measured. The mixer exhibits a maximum conversion gain of about 0 dB in the frequency range of 32 GHz-38 GHz with an intermediate frequency (IF) of 100 MHz and an IF load of 50 /spl Omega/. With an external IF matching network a conversion gain up to 5 dB can be achieved. The mixer which consists of one pseudomorphic HFET represents state of the art performance. >

The feasability of monolithic millimetre-wave front-ends based on a GaAs MESFET technology has been demonstrated. Different specific MMIC circuit functions have been fabricated using a 0.25 ?m GaAs MESFET technology. Mixer, doubler and switch MMIC circuits have been realised using Schottky diodes as active elements. The diode performances have been improved by including a selective n+ buried layer for reduction of the series resistance. Voltage controlled oscillator and amplifier have been fabricated using the same technology without n+ layer.

A technology is described which allows the monolithic integration of millimeter-wave Schottky diodes and MESFETs on one chip. The Schottky diodes have a cutoff frequency f/sub T/ of 2300 GHz. A monolithic 60-GHz mixer chip using these diodes shows a conversion loss of 6 dB and a noise figure (DSB) of 3.3 dB. The MESFETs have an f/sub max/ up to 70 GHz. A two-stage IF amplifier realized with this technology shows a gain of 20.6 dB and a noise figure of 1.7 dB at 4 GHz. >

We report here on low-frequency (LF) noise of GaAs/ GaAlAs TEGFET's. Present investigations show that this noise is not inherently lower in TEGFET's than in MESFET's. Moreover, the bias and frequency dependence of the noise was found to indicate that traps in GaAlAs have a fundamental influence on LF noise. A close correlation is subsequently observed between the noise level at ambient temperature and the TEGFET static and dynamic performances at low temperature (130 K).