Abstract: In response to changes in an input binary digital signal, a 3rd order cosine pulse waveform, which, when it is changed in the increasing direction, has “0” level in a first period of T/12 (T corresponding to one-half cycle of the binary digital signal), is changed as a waveform of (h/2)(1+cos(3?t/T)+?/4) in the next period of 4T/12 (?5T/12?t??T/12) and has an h (constant) level in the remaining period of T/12, and when it is changed in the reducing direction, has the h level in the first period of T/12, is changed as a waveform of (h/2)(1+cos(3?t/T)??/4) in the next period of 4T/12 (T/12?t?5T/12) and also has “0” level in the remaining period of T/12. By using this pulse wave, a flat part is generated in a time width of T/12 with respect to a judgment point. It is thus possible to improve the immunity to the effects of digital signal jitter, obtain change judgment with a sole single pulse and reduce the circuit scale and the power consumption.

Abstract: In response to changes in an input binary digital signal, a 3rd order cosine pulse waveform, which, when it is changed in the increasing direction, has “0” level in a first period of T/12 (T corresponding to one-half cycle of the binary digital signal), is changed as a waveform of (h/2)(1+cos (3&pgr;t/T)+&pgr;/4) in the next period of 4T/12 (−5T/12≦t≦−T/12) and has an h (constant) level in the remaining period of T/12, and when it is changed in the reducing direction, has the h level in the first period of T/12, is changed as a waveform of (h/2)(1+cos(3&pgr;t/T)−&pgr;/4) in the next period of 4T/12 (T/12≦t≦5T/12) and also has “0” level in the remaining period of T/12. By using this pulse wave, a flat part is generated in a time width of T/12 with respect to a judgment point.

Abstract: In an NPN type bipolar transistor, by employing AlGaAs or InGaAs having greater band gap than silicon, for an emitter and a base, doping amount of the emitter can be made smaller than that of the base to permit improvement of reverse withstanding voltage between the base and the emitter. Therefore, B class or C class bias can be used in a microwave band to improve efficiency.