Automatic microwave gain control device

• US 6,069,528 A
• Filed: 07/31/1998
• Issued: 05/30/2000
• Est. Priority Date: 07/31/1997
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Kashima, Yukiro
• Primary Examiner(s): Mottola, Steven J.
• Application Number:
  US09/127,302
• Time in Patent Office: 669 Days
• Field of Search: 330/53, 330/54, 330/129, 330/140, 330/284, 330/286
• US Class Current: 330/53
• CPC Class Codes: H03G 3/3042 in modulators, frequency-changers, transmitters or power amplifiers transmission power control in bidirectional transmission systems H04W52/04

Abstract

An automatic microwave gain control device comprises a signal amplifier, a directional coupler coupled to one terminal of the signal amplifier for receiving a portion of an amplified microwave signal power, a microwave detection diode connected to one end of the directional coupler, a bias supply circuitry supplying an adjustable D.C. bias voltage to the microwave detection diode, a D.C. amplifier for amplifying a voltage derived from an addition of a microwave detection output voltage of the microwave detection diode and the bias voltage of the bias supply circuitry, and a variable attenuator provided at another side of the terminals of the signal amplifier, wherein the variable attenuator controls an output power outputted from an output terminal to be constant power by way of controlling a magnitude of attenuation of the signal at the another terminal of the signal amplifier according to an output voltage of the D.C. amplifier. This is done so as not to be affected by dispersion of characteristic and dispersion of mounting position of the microwave detection diode.

Claims

1. An automatic microwave gain control device comprising:

signal amplifier for amplifying a microwave signal;

a directional coupler for receiving at least a portion of said amplified microwave signal;

a bias supply circuitry supplying an adjustable D.C. bias voltage;

microwave detection means for rectifying an addition of said D.C. bias voltage and said portion of said amplified microwave signal;

a D.C. amplifier for amplifying said addition of said D.C. bias voltage and said portion of said amplified microwave signal after rectification;

a variable attenuator, coupled to an output terminal of said D.C. amplifier, for varying attenuation in order to maintain an output signal of said automatic microwave gain control device substantially constant; and

a strip line-waveguide converter coupled to said directional coupler, for converting a TEM wave into a waveguide mode.

4. The automatic microwave gain control device according to claim 1, further comprising a microwave output power regulating terminal for impressing a D.C. bias voltage from said bias supply circuitry.

2. An automatic microwave gain control device comprising:

a signal amplifier for amplifying a microwave signal;

a directional coupler for receiving at least a portion of said amplified microwave signal;

a bias supply circuitry supplying D.C. bias voltage;

microwave detection means for rectifying an addition of said D.C. bias voltage and said portion of said amplified microwave signal;

a D.C. amplifier for amplifying said addition of said D.C. bias voltage and said portion of said amplified microwave signal after rectification;

variable attenuator, coupled between an output terminal of said D.C. amplifier and an input terminal of said signal amplifier, for varying attenuation in order to maintain an output signal of said automatic microwave gain control device substantially constant; and

a waveguide-strip line converter coupled to said directional coupler, for converting a waveguide mode into a TEM wave.

3. The automatic microwave gain control device according to claim 2, further comprising at least one low noise amplifier situated between said directional coupler and said waveguide-strip line converter.

5. An automatic microwave gain control device comprising:

a signal amplifier for amplifying a microwave signal, said signal amplifier is provided with an intermediate frequency amplifier at an input side terminal thereof, a microwave signal amplifier at an output side terminal thereof, and a frequency converter;

a directional coupler for receiving at least a portion of said amplified microwave signal;

a bias supply circuitry supplying D.C. bias voltage;

microwave detection means for rectifying an addition of said D.C. bias voltage and said portion of said amplified microwave signal;

D.C. amplifier for amplifying said addition of said D.C. bias voltage and said portion of said amplified microwave signal after rectification;

a variable attenuator, coupled to an output terminal of said D.C. amplifier, for varying attenuation in order to maintain an output signal of said automatic microwave gain control device substantially constant; and

a strip line-waveguide converter coupled to said directional coupler, for converting a TEM wave into a waveguide mode.