coupling of 2nd harmonics gsm

Hi All,

Could guys raise your points about the different contribution of
GSM second harmonic ? If the conducted link budget is highly safe
in margin ? If possbile, I need you to comment more on Power amplifier
supply leakage sources and remedy...

Thanks

Appropriate decoupling cap. at ' PA VDD ' and ' PA power Control ' etc pins can help on improving 2nd harmonic.

- Use decoupling capacitors with SRF at second harmonic.
- Increase the parasitic coupling between signal paths of low bands (850/900MHz) and high bands (1800/1900MHz). The coupling shall be greater than 30dB.
- Try to calibrate the last PCL with 1dB lower (it will improve the talk-time and harmonics)

Hi vfone,

Could I know:
1. How to increase parasitic coupling between LB and HB ? by layout ? If restricted
small spacing between LB / HB PA output tracks, how can I do.
2. Last PCL means maximum PCL ? I found max PCL harmonic is somtime
related to PA VDD voltage regulation capability upon ramping.

Hi sir, How comes control signal to PA can make 2nd harmonic lower by bypassing ?

Thanks!