The inventors have been Studying heterojunction bipolar transistors which are excellent in
high-frequency character istics. The inventors investigations have revealed that there are …

It is an object of the present invention to provide a mixer/amplifier circuit for producing IF
signals from signals of different levels in different frequency bands such as VHF and UHF …

In accordance with the illustrated preferred embodi ment, the present invention provides a
self-oscillating mixer with Darlington-connected transistors and a feed back resonator. The …

The problem of switching outputs and of mixing sig nais of two frequencies are frequently
encountered in electronic circuits. For these purposes it has been pro posed to use pairs of …

A single sideband mixer is constructed with digital logic elements such as T-type flip-flops
and inverters and with FETs, and the resulting mixer circuit simultaneously improves control …

A high conversion efficiency harmonic signal mixer is provided by employing in a mixer
circuit a non-rectifying semiconductor device having a generally symmetric response in the …

57 ABSTRACT A heterojunction bipolar transistor includes a collector con tact layer
constituted by a high-concentration first semicon ductor layer of a first conductivity type …

Mixer circuits-circuits in which two AC inputs are combined to produce an output signal the
frequency of which represents the sum or difference of the input fre quencies-are in wide …

US4794440A - Heterojunction bipolar transistor - Google Patents US4794440A - Heterojunction
bipolar transistor - Google Patents Heterojunction bipolar transistor Download PDF Info …

57 ABSTRACT A heterojunction bipolar transistor of this invention is a miniaturized
heterojunction bipolar transistor wherein at least one of an emitter layer and a collector layer …