DIRECTIONAL DIODE EXPANDER

• US 3,808,561 A
• Filed: 11/29/1967
• Issued: 04/30/1974
• Est. Priority Date: 11/29/1967
• Status: Expired due to Term

• Current Assignee: Robert F. Sullivan, Robert V. Garver
• Original Assignee: Robert F. Sullivan, Robert V. Garver
• Inventors: Sullivan, Robert F., Garver, Robert V.
• Primary Examiner(s): Wilbur, Maynard R.
• Assistant Examiner(s): Berger, Richard E.
• Application Number:
  US04/687,418
• Time in Patent Office: 2,344 Days
• Field of Search: 323/74 333/81,81A,24,24.2,17
• US Class Current: 333/17.1
• CPC Class Codes: G01S 1/02 using radio waves G01S19/00 takes precedence
• CPC Class Codes: H01P 1/222 Waveguide attenuators H01P1/23 takes precedence
• CPC Class Codes: H01P 1/225 Coaxial attenuators H01P1/23 takes precedence
• CPC Class Codes: H03G 7/001 without controlling loop H03G7/007, H03G7/02, H03G7/06 take precedence

Abstract

A diode expander for use in applications in which bi-directional power flow is encountered, said expander having a varactor diode and a PIN diode so placed in a transmission line that, at medium power, power flows in one direction but not in the other. Both diodes will tend to give a high attenuation in the low power state and a low attenuation in the high power state. The varactor must be selected to be a better rectifier than the PIN diode. For forward medium power flow the varactor is encountered first rectifying the power and biasing the PIN diode into the low loss state. For reverse medium power flow the PIN diode will be first encountered. Because the PIN diode is selected to be a poorer rectifier than the varactor a higher threshold of transmission will exist in the direction of reverse power flow.

Claims

1. A microwave power transmission device having two ports and including a means for providing different threshold levels of conduction for different directions of propagation, said means comprising:

a. a first diode means and a second diode means, said second diode means being selected to have a poorer recitification characteristic than said first diode means;

b. said first and second diode means being placed within said transmission device in a spaced relation such that power flowing in one direction will encounter said first diode means before said second diode means and power flowing in an opposite direction will encounter said second diode means before encountering said first diode means; and

c. a circuit means for providing a dc current path between said first and said second diode means, whereby when microwave power is flowing into said transmission device in said one direction it will impinge upon said first diode means causing a dc current to flow from said first diode means to said second diode means and when microwave power enters said transmission device from said opposite direction it will encounter said second diode means and will be substantially reflected until relatively higher power levels are used.

2. The power transmission device of claim 1 in which said second diode means comprises two diode switches having a poorer rectification characteristic than said first diode means, said two diode switches being connected in parallel.

3. A diode expander having different thresholds of conduction for different directions of propagation, comprising:

a. a first port and a second port, b. a first diode, c. a second diode, said second diode being selected to have a poorer rectification characteristic than said first diode, d. a transmission line connecting said first and said second diode in series, said series combination of diodes being connected in series between said first port and said second port, and e. a dc current circuit means for allowing a dc current to flow between said first and said second diodes, while excluding rf current from said dc circuit.

4. The diode expander of claim 3 in which the dc circuit means comprises a grounded quarter-wave length transmission line connected in parallel between said first port and said first diode, a second grounded quarter-wave length transmission line connected in parallel between said second diode and said second port and saId transmission line connecting said first and said second diode in series.

5. The diode expander of claim 4 in which said first diode is a varactor and said second diode is a PIN diode.