1. microwave frequency PCB board is not only the support of the circuit, or microwave electromagnetic field transmission medium. Therefore, the best choice for high-frequency RF circuit PCB, microwave plate.
2. RF circuit traces on the PCB to consider in addition to the general principles of the current size, but also must consider the characteristic impedance of the printed line, strict impedance matching, must be considered when making impedance control PCB printed lines. Characteristic impedance traces and material properties and physical parameters related to PCB, PCB designers must be clear so that the performance of PCB boards.
3. RF circuit boards generally have a high frequency of high-performance features, precision usually choose high dielectric constant, low loss characteristics of stability and substrate. In addition, the substrate must comply produce processing, such as high temperature reflow soldering. The most commonly used RF substrate is FR4, TACONIC and ROGERS company's series of plates.
4.FR4 (flame retardant epoxy glass cloth copper clad laminates), dielectric constant at 1GHz frequency test for Er = 4.3 ± 0.2, glass transition temperature Tg = 135 ℃. Ordinary sheet metal plate used in the following two ways: ordinary sheet, low cost, mature technology; UV sheet, commonly known as yellow plate, there are UV-BLOCKING function block ultraviolet rays, mainly for the outer layer of the PCB. Performance is slightly better than ordinary sheet metal.
5.TACONIC company brand is good, complete specifications, the price is relatively FR4 higher.
High dielectric constant material 6.ROGERS's accuracy, good temperature stability, low loss, commonly used in high-power circuit and PCB manufacturing, processing technology and FR4 same low cost, but a small copper adhesion.