GaAs FET direct frequency-modulators for 42-GHz-band HDTV radio cameras and 7-GHz-band field pick-up transmitters

Author

Mitsumoto, H. ; Imai, K.

Author_Institution

NHK, Tokyo, Japan

fYear

1993

Firstpage

663

Abstract

The design of a direct frequency-modulator with high modulation sensitivity is described. With a dielectric resonator, two hyper-abrupt-junction varactors, and a GaAs FET, this design achieves a modulation sensitivity greater than 20 MHz/V in a 42-GHz-band frequency modulator developed for HDTV (high-definition television) radio cameras. When this design is used in a 7-GHz-band frequency modulator for a field pick-up transmitter gathering emergency news, it provides an output power of 22 dBm, a differential gain of less than 3%, and a differential phase of less than 2 degrees . All transmitters using this frequency modulator have a high broadcast efficiency.<>

Keywords

III-V semiconductors; colour television cameras; frequency modulation; gallium arsenide; high definition television; modulators; solid-state microwave circuits; television transmitters; 42 GHz; 7 GHz; FET direct frequency-modulators; GaAs; HDTV radio cameras; dielectric resonator; field pick-up transmitters; high modulation sensitivity; high-definition television; hyper-abrupt-junction varactors; Cameras; Dielectrics; FETs; Frequency modulation; Gallium arsenide; HDTV; Phase modulation; Radio transmitters; TV; Varactors;

fLanguage

English

Publisher

ieee

Conference_Titel

Microwave Symposium Digest, 1993., IEEE MTT-S International

Conference_Location

Atlanta, GA, USA

ISSN

0149-645X

Print_ISBN

0-7803-1209-0

Type

conf

DOI

10.1109/MWSYM.1993.276994

Filename

276994