PIN diode network for multiband RF coupling

• US 20070252666A1
• Filed: 04/28/2006
• Published: 11/01/2007
• Est. Priority Date: 04/28/2006
• Status: Active Grant

• Current Assignee: ARRIS Enterprises LLC (CommScope Holding Company, Inc.)
• Original Assignee: Ruckus Wireless, Inc. (CommScope Holding Company, Inc.)
• Inventors: Shtrom, Victor
• Granted Patent: US 7,639,106 B2
• Time in Patent Office: Days
• US Class Current: 333/262
• CPC Class Codes: H01P 1/15 by semiconductor devices
• CPC Class Codes: H03H 5/12 with at least one voltage- or current-dependent element
• CPC Class Codes: H03H 7/25 comprising an element controlled by an electric or magnetic variable H03H7/27 takes precedence
• CPC Class Codes: H03K 17/74 by the use, as active elements, of diodes by the use of more than one type of semiconductor device H03K17/567; by the use of tunnel diodes H03K17/58; by the use of negative resistance diodes H03K17/70

Abstract

A PIN diode network includes a parallel inductor. In the off state of the PIN diode, the inductor forms a resonant tank circuit in parallel with the PIN diode. The inductor is selected based on the stray capacitance of the PIN diode so that the self resonant frequency (SRF) of the tank circuit is at or near the desired operating frequency. At the operating frequency, the impedance of the tank circuit is essentially infinite. At the operating frequency, isolation is improved for the PIN diode network as compared to a PIN diode alone. The PIN diode network allows a lower specification PIN diode to operate with higher isolation. The PIN diode network allows a lower specification PIN diode to operate at a higher frequency than would otherwise be possible due to intrinsic stray capacitance of the PIN diode.

Claims

1. A PIN diode network, comprising:

an input port;

an output port;

a PIN diode configured to selectively couple the input port to the output port by application of a forward bias to the PIN diode, the PIN diode having a stray capacitance in an off state upon removal of the forward bias;

a first inductor in parallel with the PIN diode, the first inductor configured to self-resonate at a first operating frequency of the PIN diode network with the stray capacitance of the PIN diode when the PIN diode is in the off state; and

a second inductor in parallel with the PIN diode, the second inductor configured to self-resonate at a second operating frequency of the PIN diode network with the stray capacitance of the PIN diode when the PIN diode is in the off state.

2. The PIN diode network of claim 1 wherein the PIN diode network has improved isolation between the input port and the output port at the first operating frequency as compared to an isolation of the PIN diode alone between the input port and the output port.

3. The PIN diode network of claim 1 wherein the first operating frequency is in the range of about 2.4 to 2.4835 GHz.

4. The PIN diode network of claim 1 wherein the second operating frequency is in the range of about 4.9 to 5.835 GHz.

5. The PIN diode network of claim 1 wherein the first operating frequency of the PIN diode network is determined based on the equation:

6. The PIN diode network of claim 1 wherein the first inductor is in series with the second inductor.

7. The PIN diode network of claim 1 wherein the first inductor in parallel with the PIN diode are configured to form an equivalent tank circuit at the first operating frequency.

8. The PIN diode network of claim 1 wherein the first inductor in parallel with the PIN diode are configured to form a band-stop filter at the first operating frequency.

9. A method, comprising:

receiving into an input port a first frequency and a second frequency, the input port selectively coupled to an output port by a PIN diode;

if the PIN diode is forward biased, coupling the first frequency and the second frequency to the output port;

otherwise, blocking the first frequency by self resonance of a first inductor and a stray capacitance of the PIN diode and blocking the second frequency by self resonance of a second inductor and the stray capacitance of the PIN diode.

10. The method of claim 9 wherein the first inductor is in parallel with the PIN diode.

11. The method of claim 9 wherein the first inductor is in series with the second inductor, the first inductor and the second inductor in parallel with the PIN diode.

12. The method of claim 9 wherein the first frequency is determined based on the equation:

13. The method of claim 9 wherein blocking the first frequency by self resonance comprises forming an equivalent tank circuit of the first inductor and the PIN diode.

14. A system for multiband RF coupling, comprising:

an input port for receiving a first frequency and a second frequency;

an output port; and

means for selectively isolating the first frequency and the second frequency from the output port.

15. The system for multiband RF coupling of claim 14 wherein the means for selectively isolating includes a first means for isolating the first frequency in series with a second means for isolating the second frequency.

16. The system for multiband RF coupling of claim 14 wherein the first means for isolating the first frequency comprises an inductor in parallel with a PIN diode, the inductor and the PIN diode configured to resonate at the first frequency when the PIN diode is in an off state.

17. The system for multiband RF coupling of claim 14 wherein the first means for isolating the first frequency comprises a first inductor, the second means for isolating the second frequency comprises a second inductor, the first inductor and the second inductor in series, the first inductor and the second inductor in parallel with the PIN diode, the first inductor and the PIN diode configured to resonate at the first frequency when the PIN diode is in an off state, the second inductor and the PIN diode configured to resonate at the second frequency when the PIN diode is in an off state.

18. The system for multiband RF coupling of claim 14 wherein the means for selectively isolating the first frequency and the second frequency comprises a PIN diode between the input port and the output port, further wherein the isolation of the means for selectively isolating is greater than an isolation of the PIN diode alone between the input port and the output port.