rf prototyping technique
RF signal traces within the board are made from a type of transmission line known as microstrip – flat copper strips connecting various signal destinations. Microstrip impedance is a function of line width and other factors. In general, wide lines have low characteristic impedance with the value rising as the width narrows.
Line impedance within the board is generally less important at lower frequencies (HF) but becomes more critical at UHF frequencies and above. At microwave frequencies, sections of microstrip are used to synthesize capacitors and inductors for resonating and impedance matching, making both length and shape of each trace critical.
Re: rf prototyping technique
– Keep paths short and direct – especially ground connections
– Keep power and RF paths apart to avoid unwanted coupling.
– Consider including test points to permit monitoring signals at key nodes.
– Consider using topside grounds to provide additional isolation between high gain
inputs / outputs. (Topside grounds are connected to the ground plane by periodic via
holes soldered on both sides.)