RF / Microwave PC Board Design and Layout Base Materials for High Speed, High Frequency PC Boards

· Unlike digital, analog signals can be at any voltage and current level (between their min & max), at any point in time. · Standard analog signals are assumed to be between DC and a few hundreds of MHz. · RF/Microwave signals are one frequency or a band of frequencies imposed on a very high frequency carrier. · RF/Microwave Circuits are designed to pass signals within band of interest and filter energy outside that range. · Signal band can be narrow or wide.- Narrow band circuits usually have pass band less than 1 MHz.- Broad band circuits pass a range of frequencies up to tens of MHz. · When digital and microwave exist in the same unit, pass bands of microwave circuits usually fall (by design) outside the harmonic range of the digital signals. · RF / Microwave PC Board layout simply follows the “Laws of Physics”-· When laws of physics can’t be followed, know what compromises are available. · Microwave signals are very sensitive to noise, ringing and reflections and must be treated with great care. · Need complete impedance (Zo) matching (50 ohm out / 50 ohm line / 50 ohm in).- Minimizes Return Loss / VSWR