Monolithic Circuit Applications Research Articles

Integration of high-Q GaAs varactor diodes and 0.25 mu m GaAs MESFET's for multifunction millimeter-wave monolithic circuit applications

Two technologies are demonstrated whereby high-Q, vertical-structure, abrupt-junction varactor diodes are monolithically integrated with 0.25- mu m GaAs MESFETs on semi-insulating GaAs substrates for multifunction millimeter-wave monolithic circuit applications. Diodes with various anode sizes have been realized with measured capacitance swings of >2.1:1 from 0 V to -4 V and series resistances of approximately 1 Omega . Diodes having a zero bias capacitance of 0.35 pF have Q's of >19000 (50 MHz) with -4 V applied to the anode. Under power bias conditions, the MESFETs have a measured gain of >6 dB at 35 GHz with extrapolated values for f/sub t/ and f/sub max/ of 32 GHz and 78 GHz, respectively. Using these technologies, a monolithic Ka-band voltage controlled oscillator (VCO) containing a varactor diode, a 0.25- mu m GaAs MESFET, and the usual MMIC passive components has been built and tested. At around 31 GHz, the circuit has demonstrated 60-mW power output with 300 MHz of tuning bandwidth. >

Some applications of monolithic circuits in telemetry : J. R. Groves, Proc. I.R.E.E. Australia, May (1968), p. 164

Some applications of monolithic circuits in telemetry : J. R. Groves, Proc. I.R.E.E. Australia, May (1968), p. 164

Designing digital monolithic integrated circuits

In order to properly design or specify integrated circuits, the circuits engineer today must not only train himself in semiconductor component theory and design principles, but he must also become thoroughly familiar with the technology limitations that govern the manufacture of integrated circuits. So far, there is no set of design rules that apply generally to the great variety of circuits that may be required. The design approach to digital circuits, for example, can be entirely different from that of linear circuits from the standpoint of both technical and economic considerations. Yet an excellent insight into integrated circuit design can be obtained by following the theory and design procedure for translating a typical digital circuit design into a final monolithic device. In the following discussion, the highlights of integrated circuit theory, design relationships, processes and parameters will be developed to cover most of today's applications of monolithic circuits in digital computers. The vehicle for this is a high-speed DTL NAND gate, Fig. 1, currently being manufactured in quantity by Motorola.