PURPOSE: To prevent generation of a spurious oscillation and an unstable operation in an active circuit of an amplifier, etc. by providing a radio wave absorbing body on a high impedance part of a DC return circuit choke pattern.
CONSTITUTION: A DC return circuit choke pattern for applying a bias of an active circuit is constituted of low impedance parts 391, 392 of 1/4 wavelength and high impedance parts 381, 382 of 1/4 wavelength. On the high impedance part 382, a radio wave absorbing body 40 is placed as shown by an A-A' section in the figure. According to this constitution, even in case when a circuit by said choke pattern operates as a positive feedback path of an amplifier, with respect to other frequency component than a signal frequency, said radio wave absorbing body 40 operates as a damper, therefore, in an active circuit of an amplifier, etc., generation of a spurious oscillation and an unstable operation can be prevented.
KOBAYASHI KOUZOU
TSURUMARU SHINOBU
| JPS596305B2 | 1984-02-10 | |||
| JPS4734824U | 1972-12-18 | |||
| JPS52132656A | 1977-11-07 | |||
| JPS5111743B1 | 1976-04-13 |