we tried contacting the support over email & forum, no help received in time.we already lost 3 months of time trying to tune the antenna.
we have choosen your M25007-1 for a tracker device, which is planning to put in to production around 10K PCS a month. but the antenna issue thrown us away from the production planning dates,and we are badly screwed. we tried contacting over forum, sadly no reply on forum.
here is the VNA images of the antenna tuning. we tried to built a pcb with only m25007-1,and its circuitry,powered by a coil cell, and we attached a VNA to tune it. VNA calibraed with extra cable also attached. please have a look at the pics.
we also tried getting the VNA return loss between antenna and sawfilter near the capacitor.
we feel that we tuned the antenna to 1575Mhz, but the gps receiver cant see any satellites in opensky also.. the same gps when it is connected with a flex strip antenna it tracks 5 to 6 satellities with in 30secs and gets the fix with in 100secs.so gps firmware and circuit is correct. but when antenna input is supplied from the M25007-1 we dont see even a single satellite tracking.
board is 25mm x50mm, metal clearance rules followed correctly under the antenna, and At1 -0ohms, At2 -1nH. 3V powered. 2 Layer-FR4 PCB.
we already lost 3 months of time, trying to tune and get some help..our managers gave strict warning that, if it not resolved with in this weekend,then we got to remove the antennova part and move with custom LNA and flexstrip iteration..we hope your team will support us in time, so that we have your part in our product,and there will be huge production qty is planned. Thank you
VNA with tuned antenna -return loss at gps receiver input..extreme output of the antenna
VNA with open cable calibrated
VNA input attached to the antenna ,capacitor infront of the saw filter and output as below, 3v supplied.
we are new to RF world,and Antenna tuning, we dont even know if VNA is properly ,and we are new to smith charts and phases etc...anyway but can be understood and with the help of your guidance we hope we can able to get the device up and running.Thank you