PCB Circuit Board Material Selection for Different 5G Frequency Bands (Part 2)

What material is recommended for 60-70GHz?

In addition, it is determined according to your specific application scenarios and indicators. Generally speaking, RO4350B/RO4835 and its LoPro version and other materials can be given priority, and then use RO3003 materials and other panels with less loss.

What is the difference between dielectric constant (process) and dielectric constant (design)?

It is a different result under different measurement methods, among which DesignDk is a parameter used for actual circuit simulation and design.

Will LoPro technology affect the accuracy of line etching?

Compared with ordinary electrolytic copper foil, LoPro copper foil is smooth and helps fine circuit etching.

Using different forms of microstrip lines, strip lines and coplanar waveguides, does the use of Dk in the specification differ greatly from the actual situation?

The Dkonthe specification usually refers to the Dk of the media. In different circuit structures, due to the electromagnetic field distribution, the equivalent Dk of the circuit is different. The design Dk in the Rogers specification is based on the value of the microstrip line structure.

How to ensure the performance of pcb circuit board laminates in different humidity environments?

Our unit often encounters some differences in performance in winter and rainy days under relatively large environmental humidity. Hygroscopicity is an important indicator of PCB raw materials. There is water absorption in the parameters of the material. The smaller the value, the better. The test methods are 23 degree water immersion for 24 hours and 50 degree water immersion for 48 hours. In addition, for sheets, the double 85 test may be more demanding.

Below 6GHz, the dielectric constant is usually 3~3.7. What are the main effects of choosing a dielectric constant? When designing the SIW filter, in order to reduce the size, can you choose a larger dielectric constant, such as RT/duroid601010.2LM material?

The difference in dielectric constant will result in a difference in line width, which will affect the line insertion loss. For antenna applications, the dielectric constant also indirectly affects the gain efficiency of the antenna. Using materials with high dielectric constants is a common way to reduce the size of circuits.