Waveguide E-plane filter

Patent metadata

Field	Value
Publication number	US-9899716-B1
Application number	US-201515547998-A
Country	US
Kind code	B1
Filing date	Mar 1, 2015
Priority date	Mar 1, 2015
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

It is provided a waveguide E-plane band-pass filter comprising a tubular, electrically conductive waveguide body. An electrically conductive foil is arranged in the waveguide body and extending along a longitudinal direction of the waveguide body, the foil comprising a plurality of resonator openings. Furthermore, the waveguide body comprises at least one ridge protruding from an inner wall of the waveguide body and extending longitudinally along the longitudinal direction of the waveguide body. The foil is in mechanical contact with said at least one ridge and arranged to divide an inner volume of the waveguide body into two portions. It is also provided a diplexer, a radio transceiver, and a method for filtering a signal using such a filter.

First claim

The invention claimed is:

1. A waveguide E-plane band-pass filter comprising:
a tubular, electrically conductive waveguide body;
an electrically conductive foil arranged in said waveguide body and extending along a longitudinal direction of said waveguide body, said foil comprising a plurality of resonator openings;
wherein said waveguide body comprises at least one ridge protruding from an inner wall of said waveguide body in a plane extending into said waveguide body and extending longitudinally along the longitudinal direction of said waveguide body; and
wherein said foil is in mechanical contact with said at least one ridge and arranged extending from said ridge and in another plane substantially parallel to the plane in which said ridge extends into said waveguide body to divide an inner volume of said waveguide body into two portions.

2. The filter according to claim 1 , wherein said foil is arranged to divide said inner volume of said waveguide body into two portions of equal dimension.

3. The filter according to claim 1 , wherein a cross-section of said at least one ridge has the same shape along the full length of said at least one ridge.

4. The filter according to claim 1 , wherein said ridge comprises a plurality of protruding elements, a distance between adjacent protruding elements not exceeding a quarter of a wavelength of a center frequency of said filter.

5. The filter according to claim 1 , wherein said at least one ridge has a rectangular cross section.

6. The filter according to claim 1 , wherein said foil is in mechanical contact with a central portion of said at least one ridge along a longitudinal length of said ridge.

7. The filter according to claim 1 , wherein a size and shape of said at least one ridge is selected such that a first harmonic frequency of said filter is located at a frequency of at least 1.5 times a center frequency of said filter.

8. The filter according to claim 1 , wherein said foil is arranged along a symmetry line of said filter running along a longitudinal direction of said filter dividing said waveguide body into two symmetrical parts.

9. The filter according to claim 1 , wherein said waveguide body comprises two body elements, each body element comprising one half of said at least one ridge, and said foil being arranged at an interface between said two body elements.

10. The filter according to claim 1 , wherein said waveguide body comprises at least two body elements, and wherein one of said body elements comprises said at least one ridge.

11. The filter according to claim 1 , wherein said waveguide body has a rectangular cross-section.

12. The filter according to claim 11 , wherein said waveguide body comprises two ridges protruding from opposing walls of said waveguide body, wherein said foil is arranged extending between said two ridges.

13. The filter according to claim 12 , wherein a cross section of said two ridges has the same shape along the longitudinal length of said two ridges.

14. The filter according to claim 12 , wherein said two ridges are arranged opposing each other.

15. A diplexer unit, comprising:
a first filter according to claim 1 , said first filter configured to be operatively connected to a radio transmitter and having a first passband;
a second filter according to claim 1 , said second filter configured to be operatively connected to a receiver and having a second passband.

16. A radio transceiver comprising:
a radio transmitter;
a radio receiver;
a diplexer unit according to claim 15 operatively connected to said radio transmitter and to said radio receiver; and
an antenna operatively connected to said diplexer unit.

17. A radio transceiver module for filtering a microwave signal, the transceiver comprising:
an antenna module for transmitting and receiving a microwave signal;
a first waveguide E-plane band-pass filter module for band-pass filtering a transmission signal to form a filtered transmission signal;
a second waveguide E-plane band-pass filter module for band-pass filtering an acquired signal to form a filtered acquired signal;
both said first and second waveguide E-plane band pass filter modules comprising:
at least one internal ridge protruding from an inner wall of a waveguide body in a plane into said waveguide body and extending longitudinally along the longitudinal direction of said waveguide body; and
an electrically conductive foil, comprising a plurality of resonator openings, arranged in said waveguide body and extending along a longitudinal direction of said waveguide body, said foil being in mechanical contact with said at least one ridge and arranged extending from said ridge in another plane substantially parallel to the plane in which said ridge extends into said waveguide body to divide an inner volume of said waveguide body into two portions;

a radio transmitter module for providing said filtered transmission signal to an antenna; and
a receiver module for receiving said filtered acquired signal from said filter.

Assignees

• Ericsson Telefon Ab L M

Inventors

• Ligander Per
• Bolander Lars
• Deleniv Anatoli
• Persson Ove

Classifications

• H01P1/211

  Waffle-iron filters; Corrugated structures · CPC title

• H01Q1/246

  specially adapted for base stations · CPC title

• H01P1/2138 Primary

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

• H01Q13/085

  Slot-line radiating ends · CPC title

• H01Q5/50

  Feeding or matching arrangements for broad-band or multi-band operation · CPC title