If you are forced to use large components, you might need to clear the ground plane from under the excess pad area to reduce prasitic capacitance (at least for inductors). If the matching network component pads are larger in width than the RF feed line itself, the pads acts as stubs or capacitors and can affect the feed line characteristics. Use small matching components that have pads as wide as the RF trace.The feed line should NEVER jump over a gap in the reference ground plane below it. Never cut the ground plane under a feed line.This ensures that the RF signals will return back to the chip via a low impedance ground path. You need a solid ground plane underneath the feed line extending all the way to the RF chip’s ground pad.
We also provide reverse engineering services through which we can generate a PC board design and full Gerber data from a sample PC board. Solid ground plane underneath feed line. provides PCB design & layout services from schematics, a sample PC board or films.Avoiding bends is always preferable where possible. Use a curved trace to bend the trace is needed. The feed line should not have sharp bends or stubs on it.If the SoC or RF PA output is not 50 ohms, you must use an RLC network as necessary to convert it to 50 ohms before using a long feed line. The feed line must be designed with these common guidelines in mind: If the transmitter is a high power device radiating more than 500mW, poor feed line design or 90 degree bends can cause permanent damage to the RF SoC. If your feed trace is not 50 ohms and contains obstructions, it can detune the antenna, cause massive loss of RF signal strength both ways and ultmately reduce the range of the device drastically. A bad feed line design not only affects transmission efficiency – it affects the receiver range too. How would it not be? The trace is responsible for carrying transmitted and received signals. The antenna feed line is extremely important.