Band pass filter
Planar band pass filter includes several planar resonators (Ri) arrange parallely, such that the input (R 1 ) and output (R 5 ) planar resonators are connected to input ( 11 ) and output ( 12 ) feed lines, respectively, and the connections between the input (R 1 ) and output (R 2 ) planar resonators and the input ( 11 ) and output ( 12 ) feed lines are made by means of high impedance lines ( 14 ), respectively, such that the direction of propagation of the signal from the input to the output of the filter remains invariable between the feed lines, the high impedance lines ( 14 ), the corresponding resonators, and the rest of the filter resonators.
1. A planar filter including an input and an output feeding line; wherein each of the input and the output feeding line is connected to an input and an output resonator, respectively, by high impedance lines, such that a propagation direction of a signal remains invariable across the input and the output feeding line, the connecting high impedance lines, and the input and the output resonator.
2. Filter according to claim 1 , wherein the propagation direction of the signal remains invariable through a plurality of resonators.
3. Filter according to claim 2 , including at least a finite-frequency transmission zero.
4. Filter according to claim 2 , wherein the plurality of resonators are arranged to have a gap, creating a cross coupling, between open ends of two non-contiguous resonators in the longitudinal direction.
5. Filter according to claim 1 , wherein the input and output resonators are microstrip resonators.
6. Filter according to claim 1 , wherein the input and output resonators are strip line.
7. Filter according to claim 1 , wherein the input and output feeding lines are arranged in parallel, in a longitudinal direction, with respect to the input and output resonators.
8. An input planar device suitable for demultiplexers, comprising: a planar filter including an input and an output feeding line; wherein each of the input and the output feeding line is connected to an input and an output resonator, respectively, by high impedance lines, such that a propagation direction of a signal remains invariable across the input and the output feeding line, the connecting high impedance lines, and the input and the output resonator; wherein the planar filter is connected to an input of a power divider.
9. Input planar device according to claim 8 , wherein the power divider is a 3 dB hybrid coupler.
10. Input planar device according to claim 9 , wherein the power divider is a 3 dB branch line.