REFLECTIONLESS AMPLIFIER

• US 3,638,134 A
• Filed: 11/26/1969
• Issued: 01/25/1972
• Est. Priority Date: 11/26/1969
• Status: Expired due to Term

• Current Assignee: Harold Seidel, Henry R. Beurrier
• Original Assignee: Harold Seidel, Henry R. Beurrier
• Inventors: Beurrier, Henry R., Seidel, Harold
• Primary Examiner(s): Kominski, John
• Assistant Examiner(s): Dahl, Lawrence J.
• Application Number:
  US04/880,016
• Time in Patent Office: 790 Days
• Field of Search: 330/85,103,107,149
• US Class Current: 330/149
• CPC Class Codes: H03F 1/345 using hybrid or directional couplers
• CPC Class Codes: H04B 3/06 by the transmitted signal

Abstract

An impedance match at the external terminals of an amplifier are simulated by cancelling any component of the signal wave reflected by the amplifier. At the input terminal of the amplifier, the cancelling wave is obtained by sampling the amplified signal and directionally coupling a portion thereof into the amplifier input network in a direction away from the amplifier. At the amplifier output terminal, the cancelling wave is obtained by sampling any wave reflected back towards the amplifier, and injecting a portion of this wave into the input end of the amplifier.

Claims

1. An electromagnetic wave system including:

an amplifier whose output terminal is coupled to a load;

means for suppressing reflections from the output terminal of said amplifier comprising;

means for sensing a wave propagating in the direction from said load towards said amplifier output terminal;

means for coupling a portion of said wave from said sensing means to the input of said amplifier;

characterized in that;

said coupled portion is amplified by said amplifier; and

in that the amplified coupled portion of said wave is equal in amplitude and is 180* out of phase with wave energy reflected at the output terminal of said amplifier.

2. The system according to claim 1 wherein said sensing means is a quadrature coupler.

3. The system according to claim 1 including a delay network disposed between said amplifier and said sensing means.

4. The system according to claim 1 including means for adjusting the amplitude and phase of said wave portion.

5. An electromagnetic wave system including:

an amplifier whose input terminal is coupled to a signal source;

means for suppressing reflections from the input terminal of said amplifier comprising;

means for directionally coupling back towards said signal source a portion of the signal wave amplified by said amplifier, said portion being equal in amplitude and 180* out of phase with wave energy reflected at the input terminal of said amplifier.

6. The system according to claim 5 including a delay network disposed between said signal source and said amplifier.

7. The system according to claim 5 including means for adjusting the amplitude and phase of said coupled portion of signal wave.

8. A reflex-match amplifier comprising:

an amplifier;

a signal source; and

an output load;

means for coupling said source to the input terminal of said amplifier including, in cascade, a first directional coupler and a first delay network;

means for coupling the output terminal of said amplifier to said load including, in cascade, a second delay network and a second directional coupler;

means connected to said second coupler for injecting a portion of reflected wave propagation in a direction from said output load towards said amplifier into the input end of said amplifier to cancel any of said reflected wave that is re-reflected at the output terminal of said amplifier;

means for extracting a component signal wave amplified by said amplifier; and

means for coupling said component of wave to said first coupler to cancel any input signal wave reflected at the input terminal of said amplifier.

9. The reflex-match amplifier according to claim 8 wherein:

said amplifier comprises a plurality of cascaded active elements;

said portion of wave is injected into the input end of one of said elements; and

wherein said component of amplified signal wave is extracted from the output end of one of said elements.

10. The reflex-match amplifier according to claim 8 wherein:

said portion of reflected wave is injected into the input end of said amplifier by means of a directional coupler; and

wherein said component of amplified signal wave is extracted from the output end of said amplifier by means of a directional coupler.

11. An electromagnetic wave transmission system comprising:

a first transmission line;

an amplifier; and

a second transmission line;

means for coupling said first line to the input terminal of said amplifier including, in cascade, a first directional coupler, a first delay network, and a second directional coupler;

means for cOupling the output end of said amplifier to said second transmission line including, in cascade, a third directional coupler, a second delay network, and a fourth directional coupler;

each of said couplers having two pair of conjugate ports;

characterized in that;

said first transmission line is connected to one port of one pair of ports of said first coupler;

the other port of said one pair of ports of said first coupler is resistively terminated;

said first delay network is coupled to one port of the other pair of ports of said first coupler and one port of one pair of ports of said second coupler;

one port of the other pair of ports of said second coupler is connected to the input terminal of said amplifier;

the other port of the other pair of ports of said second coupler is resistively terminated;

the output terminal of said amplifier is connected to one port of one pair of ports of said third coupler;

the other port of said one pair of ports of said third coupler is resistively terminated;

said second delay network is connected to one port of the other pair of ports of said third coupler and one port of one pair of ports of said fourth coupler;

one port of the other pair of ports of said fourth coupler is connected to said second transmission line;

the other port of said other pair of ports of said fourth coupler is resistively terminated;

said other port of the other pair of ports of said third coupler is coupled to the other port of said other pair of ports of said first coupler; and

the other port of said one pair of ports of said fourth coupler is coupled to the other port of said one pair of ports of said second coupler.