Millimeter wave dual-mode diplexer and method

Patent metadata

Field	Value
Publication number	US-9660316-B2
Application number	US-201414557107-A
Country	US
Kind code	B2
Filing date	Dec 1, 2014
Priority date	Dec 1, 2014
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

An embodiment millimeter wave diplexer includes a substrate integrated waveguide (SIW) high pass filter (HPF), a microstrip line low pass filter (LPF), and a T-junction. The SIW HPF is coupled to a first port, and the microstrip line LPF is coupled to a second port. The SIW HPF is operable in a first frequency band, and the microstrip line LPF is operable in a second frequency band. The T-junction is coupled between the SIW HPF and the microstrip line LPF. The T-junction is also coupled to a common port.

First claim

What is claimed is:

1. A millimeter wave diplexer, comprising:
a bottom metallic layer;
a dielectric layer coupled between the bottom metallic layer and a top metallic layer, the dielectric layer comprising a substrate integrated waveguide (SIW) high pass filter (HPF) coupled to a first port and operable in a first frequency band; and
the top metallic layer, comprising:
a microstrip line distributed L-C circuit low pass filter (LPF) coupled to a second port, and operable in a second frequency band; and
a T-junction coupled between the SIW HPF and the microstrip line distributed L-C circuit LPF on an opposite side of the first and second ports, respectively, and coupled to a common port.

2. The millimeter wave diplexer of claim 1 wherein the SIW HPF is configured to propagate a transverse electrical (TE) mode signal in the first frequency band.

3. The millimeter wave diplexer of claim 2 wherein the SIW HPF is further configured to convert a transverse electromagnetic (TEM) mode signal from the common port to the TE mode signal at the first port.

4. The millimeter wave diplexer of claim 1 wherein the microstrip line distributed L-C circuit LPF is configured to propagate a transverse electromagnetic (TEM) mode signal in the second frequency band.

5. The millimeter wave diplexer of claim 1 wherein the first frequency band comprises an E-band.

6. The millimeter wave diplexer of claim 1 wherein the second frequency band comprises a local multipoint distribution service (LMDS) band.

7. The millimeter wave diplexer of claim 1 wherein the first frequency band is distinct from the second frequency band.

8. The millimeter wave diplexer of claim 1 wherein the first port and the second port are co-located.

9. The millimeter wave diplexer of claim 1 , further comprising a via coupling the microstrip line distributed L-C circuit LPF on the top metallic layer to a pad on the bottom metallic layer.

10. The millimeter wave diplexer of claim 1 wherein the common port comprises a microstrip line port.

11. A method of constructing a millimeter wave diplexer, comprising:
forming a bottom metallic layer;
forming a dielectric layer over the bottom metallic layer, wherein the dielectric layer comprises a substrate integrated waveguide (SIW) high pass filter (HPF) operable in a first frequency band; and
forming a top metallic layer over the dielectric layer, wherein the top metallic layer comprises:
a microstrip line distributed L-C circuit low pass filter (LPF) operable in a second frequency band, and
a T-junction coupled between the microstrip line distributed L-C circuit LPF and the SIW HPF, and further coupled to a common port.

12. The method of claim 11 wherein the second frequency band comprises a local multipoint distribution service (LMDS) band.

13. The method of claim 11 , further comprising forming a via coupling the microstrip line distributed L-C circuit LPF on the top metallic layer to a pad on the bottom metallic layer.

14. The method of claim 11 wherein the SIW HPF is configured to propagate a transverse electrical (TE) mode signal in the first frequency band.

15. The method of claim 14 wherein the SIW HPF is further configured to convert a transverse electromagnetic (TEM) mode signal from the common port to the TE mode signal at a first port.

16. The method of claim 11 wherein the microstrip line distributed L-C circuit LPF is configured to propagate a transverse electromagnetic (TEM) mode signal in the second frequency band.

17. The method of claim 11 wherein the first frequency band comprises an E-band.

18. A method of diplexing a dual-band signal, comprising:
receiving the dual-band signal at a common input port;
propagating a transverse electromagnetic (TEM) mode component of the dual-band signal through a microstrip line low pass filter (LPF) tuned to a first cutoff frequency for a first frequency band, wherein propagating the TEM mode component comprises passing the TEM mode component through a distributed L-C circuit having poles corresponding to the first cutoff frequency; and
propagating a transverse electrical (TE) mode component of the dual-band signal through a substrate integrated waveguide (SIW) high pass filter (HPF) tuned to a second cutoff frequency for a second frequency band, wherein propagating the TE mode component comprises converting the TEM mode component to a TE mode component.

19. The method of claim 18 wherein the receiving the dual-band signal comprises receiving, at the common input port, the transverse electromagnetic (TEM) mode component in the first frequency band and the transverse electrical (TE) mode component in the second frequency band, wherein the first frequency band and the second frequency band are distinct frequency bands.

20. The method of claim 18 wherein the first frequency band comprises an E-band.

21. The method of claim 18 wherein the second frequency band comprises a local multipoint distribution service (LMDS) band.

22. The method of claim 18 further comprising splitting the dual-band signal at the common input port with a T-junction before propagating the TEM and TE mode components.

23. The method of claim 18 , further comprising propagating the TEM mode component to a first port after the microstrip line LPF, and propagating the TE mode component to a second port after the SIW HPF, wherein the first and second ports are co-located.

Assignees

• Huawei Tech Co Ltd

Inventors

• Zhai Wenyao
• Miraftab Vahid
• Boutayeb Halim

Classifications

• H01P1/213 Primary

  combining or separating two or more different frequencies (H01P1/215 takes precedence) · CPC title

• H01P1/2135

  using strip line filters (H01P1/2131 takes precedence) · CPC title

• H04B1/0057 Primary

  using diplexing or multiplexing filters for selecting the desired band · CPC title

• H01P1/2138

  using hollow waveguide filters (H01P1/2131 takes precedence) · CPC title