DCS Band RF filter Design Methods
Is there any method to design BPF for 1710-1880MHz band?
Hairpin structure or combline will be of more size. so please let us know with minimum size and good insertion loss, roll of is not a criteria (30dB@10% away bandwidth is fine)
regards
Chan re
Series several Mini-circuits part number components, such as seriesing LFCN-1575+, LFCN-1575+, HFCN-1600D+, HFCN-1600D+. The insertion loss maybe high, you can test it.
Smallest size design would be LC design.
High dielectric coefficient of the substrate will make the components smaller...
For instance, once upon a time, I have realize a bandpass filter ( Cauer Type II ) it had only 400umx600um on Si substrate with Er=11.9
Alumina can be a good solution..
with LC design 1710-1880MHz filter possible?
how about LC values? They are realizable?
---------- Post added at 18:09 ---------- Previous post was at 18:02 ----------
shall we get more details on the design method? helps a lot...
---------- Post added at 18:10 ---------- Previous post was at 18:09 ----------
Shall we get more about the design methodology? helps a lot
---------- Post added at 18:12 ---------- Previous post was at 18:10 ----------
Bigboss, shall we get more information about design methodology? it helps a lot....
6-pole LC tubular layout, with L=4 nH, and caps to ground 2.5-5.5 pF, coupling caps around 0.5 pF. Coil Q 200 (easily at this frequency) and cap Q 1000 (can use single layer cap or make cap from rogers pcb), you should get insertion loss of 2.5 dB or less. If you can live with less rejection, the insertion loss would be even lower with less pole design. It is not difficult to make LC filters up to 5-6 GHz as long as the bandwidth is wide enough.
By default I would choose a combline design here as it is by far the cheapest solution and can be made quite small if a short resonator length is chosen. Also, with a little experience the combline design can be achieved using the same capacitor value in all of the resonators. A ballpark design would be 15mm x 9mm in size.
tubular filter is a little large size, if you have room for it, that's good. You can also try dielectric filter.