Monolithic IC Technology Research Articles

A WATT‐level 2.3‐GHz GaAs MESFET power amplifier with gap‐coupled microstrip‐line matching topology

AbstractA one‐stage hybrid power amplifier integrated with gap‐coupled microstrip lines for impedance matching is demonstrated in this work. The gap‐coupled microstrip line amplifier module realized here can provide 15‐dB power gain, 33.5‐dBm output power, and 42% power‐added efficiency (PAE) at 2.3 GHz. The demonstrated topology is suitable in monolithic IC technology, especially in the millimeter‐wave frequency because the gap‐coupled microstrip lines can be easily compacted into small size. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 346–348, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20137

Onboard large-scale monolithic IC switch matrix for multibeam communications satellites

For future high-capacity multibeam communications satellite services, a large-scale switch matrix, in which a large number of switch elements are incorporated, is necessary and the miniaturization of each element is required. Monolithic IC technology is useful for miniaturization of such a large-scale switch matrix. In this paper, newly developed switch matrix using monolithic GaAs IC technology has presented. As the switch matrix element, monolithic switch module which includes two 2 × 2 switch ICs and two driver ICs has been developed. A manufactured 16 × 16 switch matrix using the monolithic switch modules achieves high isolation greater than 40 dB and very fast switching time of <50 ns. Using monolithic switch modules, the switch matrix size has been reduced to about one-third that of the hybrid IC type without degradation of performances.

Multigigabit-per-second optical baseband transmission system

Optical transmission baseband technology for multigigabit-per-second transmission is discussed. It is shown that a laser diode direct modulation scheme for multigigabit-per-second transmission is an extremely efficient approach to transform limited pulse transmission. The return to zero (RZ) format is effective for this approach. By the application of multigigabit-per-second monolithic IC technology, an 8-Gb/s optical regenerator and transmission experiment was successfully conducted through dispersive fiber. The experiment suggests that there is no degradation of transmission characteristics through more than 100 km of single-mode fiber within the wavelength region between zero and weak normal dispersion. >

A study on SAW voltage‐controlled‐oscillator using a method of vector summation

AbstractTo achieve ultraminiaturization of synthesizers used in mobile radio this paper proposes the use of a SAW‐VCO incorporating a vector summation technique and describes studies regarding the important parameters of frequency purity and wide‐range variability. the SAW‐VCO using the vector summation method would be composed of SAW elements and a variable gain circuit and it can be expected that they would be ultraminiaturized (using monolithic IC technology). This paper focuses on the issues of high purity and wide‐range frequency variability considering the effect that the SAW delay line has on oscillation characteristics and examines, both experimentally and theoretically, the effects that amplitude ripple has on noise characteristics. In experiments in the 800‐MHz band, a frequency variation range of about 0.5% and C/N of 67 ∼ 75 dB were obtained (C is the carrier power and N is the noise in an 8‐ kHz band with 12.5‐kHz detuning).

A Wide Range Voltage-Controlled Oscillator

An understanding of the fundamental constraints which limit the performance of controlled oscillators has permitted the development of a VCO having exceptional performance. The output frequency is relatively independent of power supply and temperature and is proportional to the controlling voltage for at least four decades. The switching circuitry is operated in a nonsaturating mode which allows frequency operation to 5 MHz. The entire circuit is compatible with monolithic IC technology.