we are using QPL9547 at VHF,UHF and 2.5 to 2.7GHz bands, we are able to get gain of 25 dB in VHF and UHF bands but in s-band gain is 7dB only. can you please provide suggest circuit in this band to get gain as per data sheet . please provide bias current details to this device.
Hi Lakshmikumari,
Please refer to page 4 of the datasheet, the EVB circuit configuration. It should provide about 13 dB gain at 4GHz. You may verify it on an EVB before design your own. The device quiescent current can be adjusted by varying the R4 value. With R4=3.32K, the Idq should be around 65mA typical. It should not impact the gain, unless the Idq is significantly low.
Best regards,
Changru Zhu