High-power PIN diode switch

1. A PIN diode single-pole, single-throw switch, comprising:

an input terminal;

an output terminal; and

first and second transmission-line elements connected in parallel to the input and output terminals, each of the first and second transmission-line elements including:

a thermoconductive dielectric substrate; and

a microstrip line disposed on the thermoconductive dielectric substrate, the microstrip line including a plurality of substantially parallel sections that are magnetically coupled, electrically connected in series, and arranged so that electrical current flows in substantially the same direction in adjacent substantially parallel sections to mutually reinforce the magnetic fields associated with the adjacent substantially parallel sections;

wherein adjacent substantially parallel sections of each of the first and second transmission lines are separated by a predetermined distance, each substantially parallel section has a predetermined width, and the predetermined distance is less than or equal to the predetermined width.

2. The PIN diode switch of claim 1 , wherein the microstrip line has a predetermined length to provide a substantially equivalent one-quarter-wavelength transmission line.

3. The PIN diode switch of claim 1 , wherein the plurality of substantially parallel sections are disposed on an outer surface of each of two thermoconductive dielectric substrates, an inner surface opposite the outer surface of at least one of the two thermoconductive dielectric substrates having an electrically conductive coating, the inner surfaces of the two thermoconductive dielectric substrates being attached to each other.

4. The PIN diode switch of claim 1 , wherein the plurality of substantially parallel sections are disposed on an outer surface of each of two thermoconductive dielectric substrates, an inner surface opposite the outer surface of each thermoconductive dielectric substrate having an electrically conductive coating, the inner surfaces of the two thermoconductive dielectric substrates being attached to opposing surfaces of a heat sink.

5. The PIN diode switch of claim 1 , wherein the plurality of substantially parallel sections are divided into at least two spatially separated groups on a single surface of the thermoconductive dielectric substrate and the thermoconductive dielectric substrate has an electrically conductive coating on a surface opposite the single surface.

6. A PIN diode single-pole, single-throw switch, comprising:

an input terminal;

an output terminal; and

first and second transmission-line elements connected in parallel to the input and output terminals, each of the first and second transmission-line elements including:

a thermoconductive dielectric substrate; and

a microstrip line disposed on the thermoconductive dielectric substrate, the microstrip line including a plurality of substantially parallel sections that are magnetically coupled, electrically connected in series, and arranged so that electrical current flows in substantially the same direction in adjacent substantially parallel sections to mutually reinforce the magnetic fields associated with the adjacent substantially parallel sections;

wherein the plurality of substantially parallel sections are divided into at least two spatially separated groups on a single surface of the thermoconductive dielectric substrate and the thermoconductive dielectric substrate has an electrically conductive coating on a surface opposite the single surface;

wherein the at least two spatially separated groups are separated by a predetermined distance sufficient to render negligible the magnetic coupling between the at least two spatially separated groups.

7. The PIN diode of claim 6 , wherein the microstrip line of each of the first and second transmission lines is arranged in a rectangular spiral.

8. The PIN diode of claim 6 , wherein the surface of the thermoconductive dielectric substrate opposite the single surface is attached to a heat sink.

9. A PIN diode switch, comprising:

a first capacitor coupled to an input terminal at a first end of the first capacitor and to a first common node at a second end of the first capacitor;

a second capacitor coupled to an output terminal at a first end of the second capacitor and to a second common node at a second end of the second capacitor;

a third capacitor coupled to a third common node at a first end of the third capacitor and to ground at a second end of the third capacitor;

a fourth capacitor coupled to a fourth common node at a first end of the fourth capacitor and to ground at a second end of the fourth capacitor;

a first PIN diode connected between the first common node and the second common node, an anode of the first PIN diode being connected with the first common node, a cathode of the first PIN diode being connected with the second common node;

a second PIN diode connected between the second common node and the fourth common node, a cathode of the second PIN diode being connected with the second common node, an anode of the second PIN diode being connected with the fourth common node;

a first control terminal connected with the third common node to provide variable bias control to the first PIN diode;

a second control terminal connected with the fourth common node to provide variable bias control to the second PIN diode;

a first transmission line coupled to the first common node at a first end of the first transmission line and to the third common node at a second end of the first transmission line; and

a second transmission line coupled to the second common node at a first end of the second transmission line and to ground at a second end of the second transmission line;

wherein:

each of the first and second transmission lines is formed as a microstrip line disposed on a thermoconductive dielectric substrate;

the microstrip line forming each of the first and second transmission lines includes a plurality of substantially parallel sections that are magnetically coupled, electrically connected in series, and arranged so that electrical current flows in substantially the same direction in adjacent substantially parallel sections to mutually reinforce the magnetic fields associated with the adjacent substantially parallel sections; and

each of the first and second transmission lines has a predetermined length to provide a substantially equivalent one-quarter-wavelength transmission line.

10. The PIN diode switch of claim 9 , wherein the first, second, third, and fourth capacitors and the first and second PIN diodes are surface mounted on the thermoconductive dielectric substrate.

11. A transmission-line element for a PIN diode switch, the transmission-line element comprising:

a thermoconductive dielectric substrate; and

a microstrip line disposed on the thermoconductive dielectric substrate, the microstrip line including a plurality of substantially parallel sections that are magnetically coupled, electrically connected in series, and arranged so that electrical current flows in substantially the same direction in adjacent substantially parallel sections to mutually reinforce the magnetic fields associated with the adjacent substantially parallel sections;

wherein adjacent substantially parallel sections are separated by a predetermined distance, each substantially parallel section has a predetermined width, and the predetermined distance is less than or equal to the predetermined width.

12. The transmission-line element for a PIN diode switch of claim 11 , wherein the microstrip line has a predetermined length to provide a substantially equivalent one-quarter-wavelength transmission line.

13. The transmission-line element for a PIN diode switch of claim 11 , wherein the plurality of substantially parallel sections are disposed on an outer surface of each of two thermoconductive dielectric substrates, an inner surface opposite the outer surface of at least one of the two thermoconductive dielectric substrates having an electrically conductive coating, the inner surfaces of the two thermoconductive dielectric substrates being attached to each other.

14. The transmission-line element for a PIN diode switch of claim 11 , wherein the plurality of substantially parallel sections are disposed on an outer surface of each of two thermoconductive dielectric substrates, an inner surface opposite the outer surface of each thermoconductive dielectric substrate having an electrically conductive coating, the inner surfaces of the two thermoconductive dielectric substrates being attached to opposing surfaces of a heat sink.

15. A transmission-line element for a PIN diode switch, the transmission-line element comprising:

a thermoconductive dielectric substrate; and

a microstrip line disposed on the thermoconductive dielectric substrate, the microstrip line including a plurality of substantially parallel sections that are magnetically coupled, electrically connected in series, and arranged so that electrical current flows in substantially the same direction in adjacent substantially parallel sections to mutually reinforce the magnetic fields associated with the adjacent substantially parallel sections;

wherein the plurality of substantially parallel sections are divided into at least two spatially separated groups on a single surface of the thermoconductive dielectric substrate and the thermoconductive dielectric substrate has an electrically conductive coating on a surface opposite the single surface;

wherein the at least two spatially separated groups are separated by a predetermined distance sufficient to render negligible the magnetic coupling between the at least two spatially separated groups.

16. The transmission-line element for a PIN diode switch of claim 15 , wherein the microstrip line is arranged in a rectangular spiral.

17. A transmission-line element for a PIN diode switch, the transmission-line element comprising:

a thermoconductive dielectric substrate; and

a microstrip line disposed on the thermoconductive dielectric substrate, the microstrip line including a plurality of substantially parallel sections that are magnetically coupled, electrically connected in series, and arranged so that electrical current flows in substantially the same direction in adjacent substantially parallel sections to mutually reinforce the magnetic fields associated with the adjacent substantially parallel sections;

wherein the plurality of substantially parallel sections are divided into at least two spatially separated groups on a single surface of the thermoconductive dielectric substrate and the thermoconductive dielectric substrate has an electrically conductive coating on a surface opposite the single surface;

wherein the surface of the thermoconductive dielectric substrate opposite the single surface is attached to a heat sink.

18. A very-high-frequency (VHF)-band plasma processing system, comprising:

a radio-frequency (RF) power supply;

a load; and

a PIN diode switch to couple selectively the RF power supply to the load, the PIN diode switch including first and second transmission-line elements, each of the first and second transmission line elements including:

a thermoconductive dielectric substrate; and

a microstrip line disposed on the thermoconductive dielectric substrate, the microstrip line including a plurality of substantially parallel sections that are magnetically coupled, electrically connected in series, and arranged so that electrical current flows in substantially the same direction in adjacent substantially parallel sections to mutually reinforce the magnetic fields associated with the adjacent substantially parallel sections, the microstrip line having a predetermined length to provide a substantially equivalent one-quarter-wavelength transmission line.

19. The apparatus of claim 18 , wherein the PIN diode switch is a single-pole, single-throw (SPST) switch.