Masami Akaike

A minaturized broad-band MMIC frequency doubler

A miniaturized broadband balanced MMIC (monolithic microwave integrated circuit) frequency double, composed of a common-gate FET and a common-source FET directly connected to each drain electrode, has been proposed and demonstrated. The doubler is designed and fabricated as a miniaturized function module using a conventional two-gate FET configuration, active trapping, and active impedance matching. The doubler design has been performed through phase error estimation, gate width optimization, and gate-source voltage optimization. The phase error estimation in a nonlinear condition has eliminated phase error compensation circuits. The fabricated chip size is only 0.5 mm*0.5 mm, which is about 1/10 the area of previously reported doublers. A conversion loss of 8-10 dB, a fundamental frequency suppression better than 17 dB, and an input return loss better than 8 dB are obtained in the output frequency range from 6 to 16 GHz. The broadband doubler as a miniaturized MMIC function module can be applicable to small-size oscillator MMICs and multifunction MMICs. >

A Nonlinear Analysis of Schottky-Barrier Diode Upconverters

A nonlinear computer analysis of Schottky-barrier diode upconverters by means of obtaining the steady-state solutions of differential equations characterized by the diode and connected circuits is shown. Both the nonlinearities of barrier resistance and capacitance are taken into consideration. The waveforms of the voltage and current at the diode, impedance, and input-output power relationships are computed for 120-GHz upconverters.

Oscillation Characteristics of Millimeter-Wave IMPATT Diodes Mounted in Low-Impedance Waveguide Mounts (Short Papers)

Experiments on dc-bias-current-tuned IMPATT diodes mounted in low-impedance waveguide mounts are described. Broad-band bias-current-tuned IMPATT oscillators were obtained which cover almost the full waveguide band; 20-, 24-, and 18-GHz tuning bandwidths were obtained with the R-500, R-620, and R-740 waveguide, respectively. From experiments it became evident that there are some suitable relations for broad-band bias tuning among the diode breakdown voltage, the oscillation frequency, and the waveguide dimension. The results are very useful for the design of the circuit and diode parameter for broad-band millimeterwave IMPATT sweep oscillators. The feasibility of applying bias-current-tuned IMPATT oscillators to a broad-band measuring instrument is expected.

A Time-Domain Large-Signal Analysis of GaAs MESFET Devices Incorporating Frequency-Domain Expression for Termination Voltages (Voltage Substitution Method)

A nonlinear large-signal analysis is proposed, in which different impedances are connected to the external circuits for different frequencies. Analysis of the performance characteristics of frequency doublers, high-efficiency amplifiers, and degenerate amplifiers using GaAs MESFETs is shown.

Mmic Research and Development

The MMIC (Monolithic Microwave Integrated Circuit) has great potential in constructing microwave equipment due to its light weight, small size, and high reliability. It is now stepping into practical application in various communications equipment. This paper presents recent research and development activities for GaAs MMICs in Japan.

Highly Reliable High-Power 86-GHz Components and Transmitter--Receiver Modules

The reliability of semiconductor active devices is related to the junction temperature of diodes used. This paper describes the reliability design and performance of 86-GHz active components and transmitter-receiver modules for a guided millimeter-wave transmission system. The components are IMPATT oscillators, IMPATT amplifiers, varactor frequency multipliers, and Schottky-barrier diode upconverters. The maximum output powers of these active devices are calculated for a given mean time between failure (MTBF). Active components and transmitter-receiver modules for 86-GHz operation were manufactured based upon the design with considerations for reliability as well as RF performance.

An Analysis of Idler-Feedback M/N Analog Frequency Dividers

An analysis of M/N analog frequency dividers, where M and N are arbitrary positive integers, is presented. These frequency dividers utilize parametric and amplification effects of an FET. The frequency division is realized by feeding back the output signal and idlers to the input ports with proper phases. Proper choices of frequency relationship, impedances, and feedback phases give phase-sensitive and frequency-stable growth of subharmonics, which is necessary to stable frequency division.