PA output Notch FilterConsideration

PA output Notch Filter type selection

n F = 433.2 MHz, 2F = 866.4 MHzn We need to put notch filter at PA output

to enhance 2 order harmonics rejectionn But, series type or shunt type ?

PA output Notch Filter type selection

n Series type is better than shunt type in all aspects

IL (dB) Rejection (dB) Impedance

Series Type 0.12 18.86 50.46 + 14.3j

Shunt Type 0.2 16.06 42.83 – 17j

PA output Notch Filter type selection

n Series type has three impedance discontinuity, butshunt type has only one

n Series type has worse impedance discontinuity(9mil => 20mil) than shunt type(9mil => 12mil)

n Impedance discontinuity effect leads to mismatch loss.In other words, series type seems to have less loss insimulation, but actually it has more loss

Stub for notch filter ?

n For shunt type, with stub,there is still impedance discontinuity effect

n In addition, the 2F rejection becomes worsethan the original one due tothe parasitic inductance.

Stub for notch filter ?

2fo Rejection (dB)With Stub 10.44

Without Stub 16.06Delta 5.6 dB

Notch Filter location

n Case A affects PA’s load-pull more than Case B.