High-frequency composite switch component

• US 20020137471A1
• Filed: 11/30/2001
• Published: 09/26/2002
• Est. Priority Date: 12/14/1999
• Status: Active Grant

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Tsurunari, Tetsuya, Satoh, Yuki
• Granted Patent: US 7,035,602 B2
• Time in Patent Office: Days
• US Class Current: 455/83
• CPC Class Codes: H01P 1/15 by semiconductor devices
• CPC Class Codes: H04B 1/0057 using diplexing or multiplexing filters for selecting the desired band
• CPC Class Codes: H04B 1/406 with more than one transmission mode, e.g. analog and digital modes
• CPC Class Codes: H04B 1/48 in circuits for connecting transmitter and receiver to a common transmission path, e.g. by energy of transmitter H04B1/46 takes precedence

Abstract

The present invention relates to a hybrid radio frequency (RF) switching device. It is an object of the invention to provide a hybrid RF switching device including fewer diodes and having a smaller size and high performance. To achieve the object according to the invention, the device includes first to fourth ports, a diode coupled between the first port and second port, a first transmission line having a length of λg/4 (where λg is a wave length of a frequency in a first frequency band), and a first element coupled in series with the first transmission line having an almost simple reactance component and nearly opening in a second frequency band. The first transmission line and first element are coupled in series between the second port and third port. The device further includes a second transmission line having a length of λd/4 (where λd is a wavelength of a frequency in the second frequency band), and a second element having an almost simple reactance component and nearly opening in the first frequency band. The second transmission line and second element are coupled in series between the second port and fourth port.

Claims

1. A hybrid radio frequency (RF) switching device for switching between a first frequency band and a second frequency being higher than the first frequency band, the hybrid radio frequency (RF) switching device comprising:

first to fourth ports;

a diode coupled between the first and second ports,

a first transmission line having a line length of g/4 n, g being a wavelength of a frequency in the first frequency band, n being an odd number of 1 or larger;

a first element coupled between the second and third ports in series with the first element, the first element having an impedance containing a nearly simple reactance component in the second frequency band;

a second element coupled at a position where the first element having a nearly open impedance in the second frequency band, the second element having an impedance containing a nearly simple reactance component; and

one of a reactance circuit and a second transmission line, the reactance circuit being coupled in parallel with the second element, the second transmission line being coupled in series with the second element, the second element having an open impedance as seen from a coupling position in the first frequency band.

2. A hybrid RF switching device of claim 1, wherein the first and second elements include surface acoustic wave (SAW) filters.

3. A hybrid RF switching device of claim 1, wherein the SAW filters include ladder type filter circuits, respectively.

4. A hybrid RF switching device of claim 1, wherein each of the ladder type filter circuits includes a SAW wave resonance element at a first stage coupled in shunt between the first transmission line and a ground, the SAW filters passing a higher frequency band of the first frequency band and second frequency band.

5. A hybrid RF switching device of claim 1, wherein the first and/or second transmission line includes a concentration constant circuit.

6. A hybrid RF switching device of claim 1,

wherein the reactance circuit comprises a parallel circuit in which an inductor and capacitor are coupled in parallel,

wherein the inductor and capacitor parallel-resonate in the second frequency band, and

wherein the inductor, capacitor, and second element resonate in the first frequency band.

7. A hybrid RF switching device of claim 6, wherein the transmission lines are composed of microstrip lines or strip lines, and the inductor in the reactance circuit is coupled directly between the transmission lines and the ground.

8. A hybrid RF switching device of claim 1, further comprising a circuit coupled in parallel with the diode, the circuit including:

a first inductor;

a second inductor coupled in series with the first inductor;

a capacitor coupled in parallel with the first inductor; and

a DC cutting capacitor coupled in series with the first inductor, wherein a circuit network including the first inductor, second inductor, and capacitor parallel-resonate in the first frequency band and second frequency band.

9. A hybrid radio frequency (RF) switching device of claim 1, handling a first frequency band, a second frequency band being higher than the first frequency band, a third frequency band near the first frequency band, and a fourth frequency band near the second frequency band, the high frequency composite switch component comprising:

first to fourth ports;

a diode coupled between the first and second ports;

a first resonance circuit parallel-resonating to have a local maximum impedance in the first and third frequency bands, and having a capacitive impedance in the second frequency band;

a first inductor coupled in shunt between the first resonance circuit and a ground;

a first capacitor coupled in series with the first resonance circuit, the first capacitor, first inductor, and first resonance circuit being coupled in a T-form;

a first surface acoustic wave (SAW) filter coupled between the first capacitor and the third port, the first SAW filter passing the second frequency band;

a second resonance circuit parallel-resonating to have a local maximum impedance in the second and fourth frequency bands, and having an inductive impedance in the first frequency band;

a second capacitor coupled in shunt between the second resonance circuit and the ground; and

a second inductor coupled in series with the second resonance circuit, the second inductor, second capacitor, and second resonance circuit being coupled in a T-form; and

a second SAW filter coupled between the second inductor and the fourth port, the second SAW filter passing the first frequency band;

wherein the first resonance circuit and second resonance circuit are coupled to the second port through the diode.

10. A hybrid RF switching device of claim 9, wherein the first SAW filter comprises:

an input terminal opposite to a side coupled to the third port; and

a SAW resonator disposed at a first stage from the input terminal and coupled to the ground in parallel, the SAW resonator series-resonating in the fourth frequency band.

11. A hybrid RF switching device of claim 9, wherein the second SAW filter comprises:

an input terminal opposite to a side coupled to the fourth port; and

a SAW resonator disposed at a first stage from the input terminal and coupled to the ground in parallel, the SAW resonator series-resonating in the third frequency band.

12. A hybrid RF switching device of claim 10, wherein a circuit in which the first resonance circuit, the first inductor coupled in shunt between the first resonance circuit and the ground, and the first capacitor coupled in series with the first resonance circuit are coupled in the T-form has an equivalent electric length of λ

d/4+λ

d×

n in the fourth frequency band, λ

d being a wavelength in the fourth frequency band, n being an integer).

13. A hybrid RF switching device of claim 11, wherein a circuit in which the second resonance circuit, the second capacitor coupled in shunt between the second resonance circuit and the ground, and the second inductor coupled in series with the second resonance circuit are coupled in the T-form has an equivalent electric length of λ

g/4+λ

g×

n in the third frequency band, λ

g being a wavelength in the third resonance frequency, n being an integer.

15. A hybrid RF switching device of claim 9, further comprising a circuit coupled in parallel with the diode, the circuit including:

a third inductor;

a fourth inductor coupled with the third inductor;

a third capacitor coupled in parallel with the third inductor; and

a DC cutting capacitor coupled in series with the third inductor,

wherein a circuit network having a capacitance between terminals of the diode turned off, the third inductor, fourth inductor, and third capacitor parallel-resonates in the first and third frequency bands and the second and fourth frequency bands.

17. A hybrid RF switching device of claim 16, wherein a frequency in the second frequency band is about twice a frequency in the first frequency band.

19. A hybrid RF switching device of claim 18, wherein a frequency in the second and third frequency bands is about twice a frequency in the first frequency band.

20. A hybrid RE switching device of claim 16 or 18, further comprising a chip choke composing a part of the switch, the chip choke inductor being mounted on the laminated body.

21. A hybrid RF switching device of claim 16 or 18, further comprising:

a grounding electrode formed in the laminated body; and

via holes coupling the grounding electrode directly with grounding terminals of the SAW filters, respectively.

22. A hybrid RF switching device of claim 21, wherein each grounding terminal is directly coupled with the grounding electrode through a plurality of via holes of the via holes.

14. A hybrid RF switching device 9, wherein a frequency in the second frequency band is about twice a frequency in the first frequency band.

16. A hybrid radio frequency (RF) switching device handling a first frequency band, a second frequency band being higher than the first frequency band, a third frequency band near the first frequency band, and a fourth frequency band near the second frequency band, the first and second frequency bands being included in a transmission band, the third and fourth frequency bands being included in a reception band, the hybrid RF switching device comprising:

a common port;

a switch for switching the transmission band and the reception band, the switch being coupled at a first stage from the common port;

a first diplexers for dividing the first and second frequency bands;

a second diplexers for dividing the third and fourth frequency bands;

first and second low-pass filters (LPFs) coupled with the first and second diplexers, respectively, the first and second LPFs corresponding the first and second frequency bands, respectively;

first and second ports coupled with the first and second diplexers through the first and second LPFs, respectively;

first and second surface acoustic wave (SAW) filters coupled with the first and second diplexers, respectively, the first and second SAW filters passing the third and fourth frequency bands included in the reception band, respectively;

third and fourth ports coupled with the first and second diplexers through the first and second SAW filters, respectively;

a laminating body including a dielectric sheet laminated therein,; and

a diode included in the switch,

wherein the laminating body includes the switch, first and second diplexers, and first and second LPFs formed therein, and includes the diode and the first and second SAW filters mounted thereon.

18. A hybrid radio frequency (RF) switching device handling a first frequency band, second and third frequency bands close to each other being higher than the first frequency band, a fourth frequency band near the first frequency band, and fifth and sixth frequency bands near the second and third frequency bands, the first, second and third frequency bands being included in a transmission band, the third, fourth, and fifth frequency bands being included in a reception band, the hybrid RF switching device comprising:

a common port;

a switch for switching the transmission band and the reception band, the switch being disposed at first from the common port;

a first diplexer dividing the first, second, and third frequency bands included in the transmission band;

a second diplexer dividing the third, fourth, and fifth frequency bands included in the reception band;

a first low-pass filter (LPF) corresponding to the first frequency band, being coupled with the first diplexer;

a first port coupled with the first diplexer through the first LPF;

a second LPF corresponding commonly to the second and third frequency bands, being coupled to the second diplexer;

a second port coupled with the second diplexer through the second LPF;

first, second, and third surface acoustic wave (SAW) filters passing the fourth, fifth, and sixth frequency bands included in the reception band,

third, fourth and fifth ports coupled with the second diplexer through the first, second, and third SAW filters, respectively;

a phase shifter for dividing the fifth and sixth frequency bands disposed between the second diplexer and the second and third SAW filters, respectively;

a laminated body including a dielectric sheet laminated therein; and

a diode included in the switch,

wherein the laminated body includes the switch, first and second diplexers, first and second LPFs, and phase shifter formed therein, and includes the diode and first, second and third SAW filters mounted thereon.