Stripline interdigital band-pass filter

Claim 2

A high frequency, stripline band-pass filter having a housing member, comprising: a first ground plane member; a second ground plane member spaced in parallel relationship to said first ground plane member; a plurality of parallel-coupled resonators disposed between said first and second ground plane members; input means for coupling input signals to the filter; output means for coupling the output of the filter to a load; and said first ground plane member being removably mounted to the filter housing member to facilitate interchanging of said first ground plane member with another ground plane member so dimensioned that the spacing between said plurality of parallel-coupled resonators and said first ground plane member is greater or less by a predetermined amount than the spacing between said plurality of parallel-coupled resonators and said second ground plane member whereby said resonators are unsymmetrically disposed between said first and second ground plane member so that the bandwidth of the filter is respectively increased or decreased.

Claim 3

The filter of claim 1 wherein said plurality of parallel-coupled resonators are cylindrical rod members.

Claim 4

The filter of claim 2 wherein said resonators have an electrical length of 90° at the mid-band frequency of the filter. 4. The filter of claim 1 wherein said plurality of parallel-coupled resonators are

Claim 5

rectangular members. 5. The filter of claim 4 wherein the electrical length of said resonators is 90° at the mid-band frequency of the

Claim 6

filter. 6. The filter of claim 1 wherein said plurality of

Claim 7

parallel-coupled resonators are interdigitalized. 7. The filter of claim 6

Claim 8

wherein said interdigitalized resonators are cylindrical rod members. 8. The filter of claim 7 wherein the electrical length of said cylindrical

Claim 9

rod members is 90° at the mid-band frequency of the filter. 9. The filter of claim 6 wherein said interdigitalized resonators are rectangular

Claim 10

members. 10. The filter of claim 9 wherein the electrical length of said

Claim 11

resonators is 90° at the mid-band frequency of the filter. 11. The filter of claim 1 wherein said plurality of parallel-coupled resonators is interdigitalized with the opposite ends of adjacent interdigital

Claim 12

resonators being connected to a short-circuit. 12. The filter of claim 11

Claim 13

wherein said interdigital resonators are cylindrical rod members. 13. The filter of claim 12 wherein the electrical length of said resonators is

Claim 14

90° at the mid-band frequency of the filter. 14. The filter of claim 11 wherein said interdigital resonators are rectangular rod members.

Claim 15

The filter of claim 14 wherein the electrical length of said resonators

Claim 16

is 90° at the mid-band frequency of the filter. 16. The filter of claim 1 wherein said input means includes connector means adapted to be directly coupled to the first one of said plurality of

Claim 17

parallel-resonators. 17. The filter of claim 1 wherein said output means includes connector means adapted to be directly coupled to a last one of

Claim 18

said plurality of parallel-coupled resonators. 18. Filter of claim 1 wherein said input means includes first connector means adapted to be connected to first one of said plurality of parallel-coupled resonators; and said output means includes second connector means adapted to be connected

Claim 19

to a last one of said plurality of parallel-coupled resonators. 19. The filter of claim 18 wherein said plurality of parallel-coupled resonators are interdigitalized and have a cylindrical structure, the opposite ends

Claim 20

of adjacent resonators being connected to a short-circuit. 20. An interdigital stripline, band-pass filter having a housing member, comprising in combination: a first ground plane member; a second ground plane member spaced in parallel relationship to said first ground plane member; a plurality of interdigitalized parallel-coupled resonators disposed between said first and second ground plane members, each resonator being attached at one end thereof to the housing member; input means for coupling input signals to the filter; output means for coupling the output of the filter to a load; and said first ground plane member being removably mounted to the filter housing member to facilitate interchanging of said first ground plane member with another ground plane member so dimensioned that the spacing between said plurality of parallel-coupled resonators and said first ground plane member is greater or less by a predetermined amount than the spacing between said plurality of parallel-coupled resonators and said second ground plane member whereby said resonators are unsymmetrically disposed between said first and second ground planes so that the bandwidth

Claim 21

of adjacent resonators being connected to a short-circuit. 20. An interdigital stripline, band-pass filter having a housing member, comprising in combination: a first ground plane member; a second ground plane member spaced in parallel relationship to said first ground plane member; a plurality of interdigitalized parallel-coupled resonators disposed between said first and second ground plane members, each resonator being attached at one end thereof to the housing member; input means for coupling input signals to the filter; output means for coupling the output of the filter to a load; and said first ground plane member being removably mounted to the filter housing member to facilitate interchanging of said first ground plane member with another ground plane member so dimensioned that the spacing between said plurality of parallel-coupled resonators and said first ground plane member is greater or less by a predetermined amount than the spacing between said plurality of parallel-coupled resonators and said second ground plane member whereby said resonators are unsymmetrically disposed between said first and second ground planes so that the bandwidth

Claim 22

of the filter is respectively increased or decreased. 21. The filter of claim 20 wherein: said input means includes first connector means adapted to be connected to a first one of said plurality of parallel-coupled resonators; and said output means includes second connector means adapted to be connected

Claim 23

to a last one of said plurality of parallel-coupled resonators. 22. The filter of claim 21 wherein each of said parallel-resonators are cylindrical rod members having an electrical length of 90° at the

Claim 24

mid-band frequency of the filter. 23. For an interdigital stripline, bandpass filter having a housing member, first and second parallel spaced ground plane members, a plurality of resonators disposed between the ground plane members, a method for varying the bandwidth of the filter including the step of varying the ground plane spacing between said first ground plane member and all of said resonators whereby all of said resonators are then unsymmetrically disposed between the ground plane members.

Claim 25

mid-band frequency of the filter. 23. For an interdigital stripline, bandpass filter having a housing member, first and second parallel spaced ground plane members, a plurality of resonators disposed between the ground plane members, a method for varying the bandwidth of the filter including the step of varying the ground plane spacing between said first ground plane member and all of said resonators whereby all of said resonators are then unsymmetrically disposed between the ground plane members.