Switching circuit including DC-DC converter cooperating with a high voltage supply and related methods
A switching circuit may include a first series diode, a second series diode, a first shunt diode coupled to the first series diode at a first control node, and a second shunt diode coupled to the second series diode at a second control node. A high voltage supply may generate a high voltage signal to be selectively applied to either the first or second control node. A dc-dc converter may cooperate with the high voltage supply to generate an intermediate bias voltage on the first and second shunt diodes so that the first series diode is reversed biased and the first shunt diode is forward biased when the high voltage control signal is applied to the first control node, and so that the second series diode is reversed biased and the second shunt diode is forward biased when the high voltage control signal is applied to the second control node.
1. A switching circuit comprising:
a first series diode;
a second series diode;
a first shunt diode coupled to said first series diode at a first control node;
a second shunt diode coupled to said second series diode at a second control node;
a high voltage supply configured to generate a high voltage control signal to be selectively applied to either the first or second control node; and
a dc-dc converter cooperating with said high voltage supply to generate an intermediate bias voltage on said first and second shunt diodes so that said first series diode is reversed biased and said first shunt diode is forward biased when the high voltage control signal is applied to the first control node, and so that said second series diode is reversed biased and said second shunt diode is forward biased when the high voltage control signal is applied to the second control node.
2. The switching circuit of claim 1 wherein said first and second series diodes are coupled in back to back relation defining an input port therebetween; and further comprising a first output port coupled to said first control node for a first frequency band, and a second output port coupled to said second control node for a second frequency band different than the first frequency band.
3. The switching circuit of claim 1 wherein said dc-dc converter comprises an isolated dc-dc converter.
4. The switching circuit of claim 1 wherein the intermediate bias voltage is less than 25% of the high voltage control signal.
5. The switching circuit of claim 1 wherein the high voltage control signal is greater than 20 volts.
6. The switching circuit of claim 1 wherein said intermediate bias voltage is less than 10 volts.
7. The switching circuit of claim 1 wherein said first and second shunt diodes each comprises a PIN shunt diode.
8. The switching circuit of claim 1 wherein said first and second series diodes each comprises a PIN series diode.
9. The switching circuit of claim 1 wherein said first shunt diode and said first series diode are coupled in an anode-to-cathode configuration; and said second shunt diode and said second series diode are coupled in an anode-to-cathode configuration.
10. The switching circuit of claim 1 further comprising at least one first filter circuit between said first shunt diode and said dc-dc converter, and at least one second filter circuit between said second shunt diode and said dc-dc converter.
11. A switching circuit comprising:
a first PIN series diode;
a second PIN series diode;
a first PIN shunt diode coupled to said first PIN series diode at a first control node;
a second PIN shunt diode coupled to said second PIN series diode at a second control node;
a high voltage supply configured to generate a high voltage control signal to be selectively applied to either the first or second control node; and
an isolated dc-dc converter cooperating with said high voltage supply to generate an intermediate bias voltage on said first and second PIN shunt diodes so that said first PIN series diode is reversed biased and said first PIN shunt diode is forward biased when the high voltage control signal is applied to the first control node, and so that said second PIN series diode is reversed biased and said second PIN shunt diode is forward biased when the high voltage control signal is applied to the second control node.
12. The switching circuit of claim 11 wherein said first and second PIN series diodes are coupled in back to back relation defining an input port therebetween; and further comprising a first output port coupled to said first control node for a first frequency band, and a second output port coupled to said second control node for a second frequency band different than the first frequency band.
13. The switching circuit of claim 11 wherein the intermediate bias voltage is less than 25% of the high voltage control signal.
14. The switching circuit of claim 11 wherein the high voltage control signal is greater than 20 volts.
15. The switching circuit of claim 11 wherein said intermediate bias voltage is less than 10 volts.
16. The switching circuit of claim 11 wherein said first PIN shunt diode and said first PIN series diode are coupled in an anode-to-cathode configuration; and said second PIN shunt diode and said second PIN series diode are coupled in an anode-to-cathode configuration.
17. The switching circuit of claim 11 further comprising at least one first filter circuit between said first PIN shunt diode and said isolated dc-dc converter, and at least one second filter circuit between said second PIN shunt diode and said isolated dc-dc converter.
18. A method of using a switching circuit comprising a first shunt diode coupled to a first series diode at a first control node and a second shunt diode to a second series diode at a second control node, the method comprising:
generating an intermediate bias voltage, from a dc-dc converter cooperating with a high voltage supply, on the first and second shunt diodes so that the first series diode is reversed biased and the first shunt diode is forward biased when a high voltage control signal is selectively applied to the first control node by the high voltage supply and so that the second series diode is reversed biased and the second shunt diode is forward biased when the high voltage control signal is selectively applied to the second control node.
19. The method of claim 18 wherein the dc-dc converter comprises an isolated dc-dc converter.
20. The method of claim 18 wherein the intermediate bias voltage is generated to be less than 25% of the high voltage control signal.
21. The method of claim 18 wherein the high voltage control signal is greater than 20 volts.
22. The method of claim 18 wherein the intermediate bias voltage is generated to be less than 10 volts.
23. The method of claim 18 wherein the first and second shunt diodes each comprises a PIN shunt diode.
24. The method of claim 18 wherein the first and second series diodes each comprises a PIN series diode.
25. A switching circuit comprising:
a first series diode;
a first shunt diode coupled to said first series diode at a first control node;
a high voltage supply configured to generate a high voltage control signal be selectively applied to the first control node; and
a dc-dc converter cooperating with said high voltage supply to generate an intermediate bias voltage on said first shunt diode so that said first series diode is reversed biased and said first shunt diode is forward biased when the high voltage control signal is applied to the first control node, and so that said first series diode is forward biased and said first shunt diode is reverse biased when a voltage reference is applied to the first control node.
26. The switching circuit of claim 25 wherein said dc-dc converter comprises an isolated dc-dc converter.
27. The switching circuit of claim 25 wherein the intermediate bias voltage is less than 25% of the high voltage control signal.
28. The switching circuit of claim 25 wherein the high voltage control signal is greater than 20 volts.