RF Microwave substrate Material Impedance
Substrate material selection principle RF Microwave
1. RF microwave band PCB board is not only the support of the circuit but also the transmission medium of the microwave electromagnetic field. Therefore, the RF Microwave circuit PCB is best to choose the high frequency and microwave plates.
2. RF microwave circuit on PCB in addition to the general principle, considering the current size, must also consider the characteristic impedance of the printed line, strict impedance matching in PCB production line control considering impedance must be printed. The characteristic impedance of printed wiring is related to the material characteristics and physical parameters of the PCB, so the PCB designer must clearly understand the performance of the PCB sheet.
3. RF microwave frequency board has high frequency and high performance and usually chooses the substrate with high dielectric constant, high stability, and low loss. In addition, the substrate must conform to the production process, such as high-temperature reflow soldering. At present, our company commonly used RF substrate for FR4, TACONIC, and ROGERS company’s series of sheet metal. See Appendix A. for details.
4. RF microwave FR4 (flame retardant copper foil, epoxy glass cloth laminate), dielectric constant at 1 GHz frequency is Er=4.3 + 0.2, glass temperature Tg=135 degrees centigrade. Ordinary sheet materials used in the following two kinds: ordinary sheet material, low cost, mature process; UV sheet material, commonly known as the yellow board, with UV-BLOCKING blocking ultraviolet function, mainly used for the outer layer of PCB board. The performance is slightly better than that of ordinary sheet metal.
5. RF microwave TACONIC company brand is good, specifications complete, the price is higher than the FR4.
6. RF microwave ROGERS, the dielectric constant of the material with high precision, good temperature stability, low loss, commonly used in the high power circuit, and PCB manufacturing, processing technology, and FR4, the processing cost is low, but the adhesion of small copper foil.
7.RF microwave Common high frequency plate substrate and its performance