Hi,
Current project is to move from a 1/4 wave whip antenna to a ceramic chip type (e.g. Johanson 1575AT43A0040). I have a pi matching network on the pcb and can look 'into' the antenna with my vector network analyser and get the conjugate impedance. I have tried to simply match that to 50 ohms (per the datasheet for the GPS receiver we are using) but it doesn't see to perform anything like as well as the 1/4 wave whip.
Question - Do I need to look 'into' the receiver chip with the VNA and match that to the antenna? If so is it still the S11 parameter I measure or something else?
TIA.
Bob
Current project is to move from a 1/4 wave whip antenna to a ceramic chip type (e.g. Johanson 1575AT43A0040). I have a pi matching network on the pcb and can look 'into' the antenna with my vector network analyser and get the conjugate impedance. I have tried to simply match that to 50 ohms (per the datasheet for the GPS receiver we are using) but it doesn't see to perform anything like as well as the 1/4 wave whip.
Question - Do I need to look 'into' the receiver chip with the VNA and match that to the antenna? If so is it still the S11 parameter I measure or something else?
TIA.
Bob