Plural switch circuits having RF propagation networks and RF terminations

• US 5,274,343 A
• Filed: 08/06/1991
• Issued: 12/28/1993
• Est. Priority Date: 08/06/1991
• Status: Expired due to Term

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Daly, Edward G. III, Russell, Mark E., Mara, John F. Jr.
• Primary Examiner(s): LEE, BENNY T
• Application Number:
  US07/740,691
• Time in Patent Office: 875 Days
• Field of Search: 333/101, 333/103, 333/104, 333/105, 333/124, 333/126, 333/129, 333/262, 307/571
• US Class Current: 333/103
• CPC Class Codes: H03K 17/162 without feedback from the output circuit to the control circuit
• CPC Class Codes: H03K 17/693 Switching arrangements with several input- or output-terminals, e.g. multiplexers, distributors logic circuits H03K19/00; code converters H03M5/00, H03M7/00

Abstract

A radio frequency circuit includes a first RF switch having a first common port coupled to an input port of the switch circuit and a first pair of branch ports and a second RF switch having a second common port coupled to an output port of the circuit and a second pair of branch ports. The radio frequency circuit further includes an RF propagation network having a first end coupled to a first one of said first pair of branch ports of said first RF switch and a second end coupled to a first one of said second pair of branch ports of said second RF switch. The radio frequency circuit further includes an RF termination having an impedance characteristic corresponding to an impedance characteristic of said first common port and having a first end coupled to a second one of said first pair of branch ports of said first RF switch and a second end coupled to a first reference potential.

Claims

1. A circuit comprising:

a first RF switch having a first common port with an impedance characteristic associated therewith and a first pair of branch ports;

a second RF switch having a second common port and a second pair of branch ports;

an RF propagation network having a first end coupled to a first one of said first pair of branch ports of said first RF switch and a second end coupled to a first one of said second pair of branch ports of said second RF switch;

an RF termination having an impedance characteristic corresponding to the impedance characteristic of said first common port and having a first end coupled to a second one of said first pair of branch ports of said first RF switch and a second end coupled to a first reference potential; and

wherein the first RF switch and the second RF switch each comprises;

a first signal path coupled between the common port and the first branch port; and

a second signal path coupled between the common port and the second branch port; and

wherein the first signal path and the second signal path each comprises;

a first and a second field effect transistor, each field effect transistor having a conductive state and a non-conductive state to provide a relatively low insertion loss characteristic when in the conductive state and a relatively high insertion loss characteristic when in the non-conductive state, each field effect transistor having a first electrode coupled to the common port of the RF switch and each field effect transistor having a second electrode coupled to the corresponding branch port of the RF switch; and

wherein the RF termination comprises;

a resistor having a first electrode and a second electrode with the first electrode coupled to the first end of said RF termination; and

a capacitor having a first electrode coupled to the second electrode of said resistor and a second electrode coupled to the first reference potential.

2. The circuit of claim 1 wherein said RF propagation network, having a signal fed thereto, has an electrical pathlength in the range of 60 to 120 electrical degrees to the signal having a pre-determined frequency.

3. The circuit of claim 1 further comprising:

a different plurality of field effect transistors, each different field effect transistor have a conductive state and a non-conductive state to provide a relatively low insertion loss characteristic when in the conductive state and a relatively high insertion loss characteristic when in the non-conductive state, each one of the different plurality of field effect transistors having a first electrode coupled to a corresponding signal path and further having a second electrode coupled to an RF ground potential.

4. A circuit comprising:

a first plurality of RF switches, each one of said first plurality of RF switches having a first common port and a first pair of branch ports wherein each one of said first common ports provides an input port of the circuit;

a plurality of RF terminations, each one of said RF terminations having a first end coupled to one of said first pair of corresponding branch ports;

a second plurality of RF switches, each one of said second plurality of RF switches having a second common port and a second pair of branch ports;

a plurality of RF propagation networks, each one of said RF propagation networks having a first end coupled to another one of said first pair of corresponding branch ports and a second end coupled to one of said second pair of corresponding branch ports; and

means for providing an RF signal path between each common port of said second plurality of RF switches and an output port of the circuit; and

wherein each one of the first plurality of RF switches and second plurality of RF switches comprises;

a first signal path coupled between the common port and the first branch port, thereof; and

a second signal path coupled between the common port and the second branch port, thereof; and

wherein the first signal path and the second signal path each comprises;

a first and a second field effect transistor, each field effect transistor having a conductive state and a non-conductive state to provide a relatively low insertion loss characteristic when in the conductive state and a relatively high insertion loss characteristic when in the non-conductive state, each field effect transistor having a first electrode coupled to the common port of the RF switch and each field effect transistor having a second electrode coupled to the corresponding branch port of the RF switch.

5. The circuit of claim 4 wherein each one of said plurality of RF propagation networks, having a signal fed thereto, is provided having an electrical pathlength in the range of 60 to 120 electrical degrees to the signal with a pre-determined frequency.

6. The circuit of claim 5 wherein each one of said RF terminations comprises:

a resistor having a first electrode coupled to the first end of said corresponding RF termination and a second electrode; and

a capacitor having first electrode coupled to the second electrode of the resistor and a second electrode of said capacitor coupled to a second end of the corresponding RF termination.

7. The circuit of claim 6 further comprising a different plurality of field effect transistors, each different field effect transistor having a conductive state and a non-conductive state to provide a relatively low insertion loss characteristic when in the conductive state and a relatively high insertion loss characteristic when in the non-conductive state, each one of the different plurality of field effect transistors having a first electrode coupled to a corresponding signal path and further having a second electrode coupled to an RF ground potential.

8. A circuit comprising:

a plurality of RF oscillators, each one of said plurality of RF oscillators providing a signal having a different frequency;

a first plurality of RF switches, each one of said first plurality of RF switches having a first common port and a first pair of branch ports with each one of said first common ports being coupled to a corresponding one of said plurality of RF oscillators;

a first plurality of resistors, each one of said plurality of resistors having a first electrode, said first electrode coupled to one of said first pair of branch ports of a corresponding one of said first plurality of RF switches, and a second electrode;

a first plurality of capacitors, each one of said plurality of capacitors having a first electrode, said first electrode coupled to the second electrode of a corresponding one of the first plurality resistors, and a second electrode coupled to ground;

a second plurality of RF switches, each one of said second plurality of RF switches having a second common port and a second pair of branch ports;

a plurality of RF propagation networks, each one of said RF propagation networks having a first end coupled to the other one of said first corresponding pair of branch ports and a second end coupled to one of said second corresponding pair of branch ports;

a second plurality of capacitors, each one of said second plurality of capacitors having a first electrode, said first electrode coupled to the other one of said second corresponding pair of branch ports, and a second electrode coupled to ground; and

means for providing an RF signal path between each one of said second plurality of common ports and an output port of the circuit.

9. The circuit of claim 8 wherein each one of said plurality of RF propagation networks comprises an electrical pathlength in the range of 60 to 120 electrical degrees for the corresponding signal provided from the RF oscillator coupled thereto.