Compact dual-mode filters for HTS satellite communication systems

Em Full-Wave Analysis and Testing of Novel Quasi-Elliptic Microstrip Filters for Ultra Narrowband Filter Design

“…From previous experience [7] and a plenty of published fullwave simulation and experimental data [13][14][15][16]25] using the same materials and EM software, it can be noted that the modeling and simulation results are expected to agree well with tests but with a relative deterioration into the IL, RL, and the F BW . This shall presumably due to extraneous factors that could not be accounted for in the simulations such as fabrication tolerance, coaxial to microstrip transition matching, cooling medium, contraction of circuits at low temperature, material quality and contact interfaces (e.g., metal/HTS).…”

“…If the two split frequencies (f 1 and f 2 ) and the Q-factor are found from a filter response either by measurement or EM simulation tool, the accurate coupling coefficient can easily be extracted using Equation (9). A dual-mode filter similar to a tested and reported one in a previous work [7] but with one zigzag step only and a suspended stripline configuration (dielectric substrate thickness h = 1 mm, ε r = 2.8 and operating frequency f o = 1.19 GHz is designed and tested with conventional conductors for this purpose.…”

“…Another HTS 11-pole hairpincomp NB microstrip filter has been reported to have a F BW of 0.6% at f o = 1.778 GHz [6]. A 2-pole and 4-pole dual-mode microstrip filters have been demonstrated at a f o = 1.39 GHz with a F BW of 1.36% [7]. A model of a 2-pole tunable microwave NB lumped-element microstrip filter has been developed, using varactor-loaded inductors and showed a possible F BW of 0.5% at f o = 980 MHz [8].…”

“…12(a), (b), (c) have regions of current peaks at various distances from each other, but all adjacent parallel and horizontal internal segments have opposite current directions. In higher order than 2-pole filters, it is relatively easy to implement and control negative cross-couplings between non-adjacent resonators to realize a quasi-elliptic response, unlike a 2-pole filter except in the case of a 2-pole dual-mode filter [7]. Therefore, an optimization process is developed and simplified to only one parameter for the EM simulation tool to achieve a quasi-elliptic response in a faster and efficient way.…”

A Modified Hair-Pin Resonator for the Design of Compact Bandpass Filter With Suppression of Even Harmonics

“…It is sometimes necessary to suppress some or all harmonic responses. Several papers have been published on compact filters employing single [1][2][3][4] and dual modes [5][6][7][8]. On the other hand, several papers have also been published on harmonic suppression [9][10][11][12][13][14][15].…”