Frequency selective limiter having reduced spike leakage
Described is a frequency selective limiter (FSL) module comprising a cascade of an FSL and a functional limiter (e.g. a conventional semiconductor limiter comprising a PIN diode) with steady state limiting and power threshold values selected such the FSL module provides suppression of a spike leakage power and while still enabling frequency selective limiting.
1. A frequency selective limiter (FSL) module comprising:
a radio frequency (RF) ferrite-based FSL having an input, an output and a steady-state limited output power characteristic; and
an RF functional limiter coupled to an output of the ferrite-based FSL, wherein the RF functional limiter is a semiconductor limiter.
2. The FSL module of claim 1 wherein the RF functional limiter comprises a plurality of semiconductor limiters.
3. The FSL module of claim 1 wherein the RF functional limiter has a power threshold characteristic which is higher than the steady-state limited output power characteristic of the RF ferrite-based FSL.
4. The FSL module of claim 1 wherein the RF functional limiter has a power threshold characteristic which is at least 0.25 dB higher than the steady-state limited output power characteristic of the RF ferrite-based FSL.
5. The FSL module of claim 1 wherein the RF ferrite-based FSL comprises a plurality of coupled RF ferrite-based FSLs.
6. The FSL module of claim 1 wherein the RF ferrite-based FSL comprises a plurality of serially coupled RF ferrite-based FSLs.
7. The FSL module of claim 1 wherein the RF ferrite-based FSL is one of:
a polycrystalline ferrite FSL; and
a single crystal ferrite FSL.
8. The FSL module of claim 1 wherein the RF functional limiter is a PIN diode limiter.
9. A frequency selective limiter (FSL) module comprising:
a radio frequency (RF) ferrite-based FSL having an input and an output; and
an RF functional limiter coupled to an output of the ferrite-based FSL, wherein the functional limiter is a gas discharge device.
10. The FSL module of claim 9 wherein the RF functional limiter comprises a plurality of gas discharge devices.
11. The FSL module of claim 9 wherein the RF functional limiter has a power threshold characteristic which is higher than a steady-state limited output power characteristic of the RF ferrite-based FSL.
12. The FSL module of claim 9 wherein the RF functional limiter has a power threshold characteristic which is at least 0.25 dB higher than a steady-state limited output power characteristic of the RF ferrite-based FSL.
13. The FSL module of claim 9 wherein the RF ferrite-based FSL comprises a plurality of coupled ferrite-based FSLs.
14. The FSL module of claim 9 wherein the RF ferrite-based FSL comprises a plurality of serially coupled RF ferrite-based FSLs.
15. A frequency selective limiter (FSL) module comprising:
a radio frequency (RF) ferrite-based FSL stage having a spike leakage characteristic; and
an RF functional limiter stage coupled to an output of the ferrite-based FSL stage, wherein characteristics of the RF ferrite-based FSL stage and the RF functional limiter stage are selected such that the combination of the RF functional limiter stage and the RF ferrite-based FSL stage provide the FSL module having a spike leakage characteristic which is reduced compared with the spike leakage characteristic of the RF ferrite-based FSL stage.
16. The FSL module of claim 15 wherein the RF functional limiter has a power threshold characteristic which is higher than a steady-state limited output power characteristic of the RF ferrite-based FSL stage.
17. The FSL module of claim 15 wherein the RF functional limiter stage comprises a plurality of RF functional limiters.
18. The FSL module of claim 15 wherein the RF functional limiter stage comprises at least one of:
a semiconductor diode;
a PIN diode; and
a gas discharge device.
19. The FSL module of claim 15 wherein the RF ferrite-based FSL stage comprises a plurality of RF ferrite-based frequency selective limiters.
20. A frequency selective limiter (FSL) module having an FSL module input and an FSL module output, the FSL module comprising:
one or more FSL stages, each of the one or more FSL stages comprising a ferrite and having an FSL stage input, an FSL stage output and a steady-state limited output power characteristic; and
one or more radio frequency (RF) functional limiter stages, each of the one or more RF functional limiter stages coupled to an output of at least one of the one or more FSL stages.
21. The FSL module of claim 20 wherein each of the one or more RF functional limiter stages has a power threshold characteristic which is higher than the steady-state limited output power characteristic of the one or more FSL stages.
22. The FSL module of claim 20 wherein the number of FSL stages does not match the number of RF functional limiter stages.
23. The FSL module of claim 20 wherein the number of FSL stages matches the number of RF functional limiter stages.
24. The FSL module of claim 20 wherein the one or more RF functional limiter stages are coupled at or after the output of the last FSL stage.
25. The FSL module of claim 20 wherein one or more of the plurality of RF functional limiters are coupled to an output of an FSL stage prior to the last FSL stage.
26. The FSL module of claim 20 wherein the FSL module comprises a plurality of RF functional limiters with at least some of the plurality of RF functional limiters coupled to one or more FSL stages prior to the last FSL stage.
27. The FSL module of claim 26 wherein at least one of the one or more RF functional limiter stages is coupled to an output of the last FSL stage.
28. The FSL module of claim 20 wherein at least one of the one or more RF functional limiter stages is coupled to an output of the FSL module.
29. A frequency selective limiter (FSL) module comprising:
a radio frequency (RF) ferrite-based FSL having an input, an output and a steady-stage limited output power characteristic; and
at least one RF functional limiter stage integrated with the RF ferrite-based FSL.
30. The FSL module of claim 29 wherein the FSL module is provided as a planar integrated FSL module.
31. The FSL module of claim 29 wherein at least one of the at least one integrated RF functional limiter stages comprises at least one of:
a semiconductor diode; and
a PIN diode.