What is a high-frequency PCB? High-frequency electronic devices are emerging today, especially in wireless networks. Satellite communications are growing rapidly, information technology is advancing to higher speeds and higher frequencies. Therefore, upgrades to a new product should always be used …
What is a high-frequency PCB?
High-frequency electronic devices are emerging today, especially in wireless networks. Satellite communications are growing rapidly, information technology is advancing to higher speeds and higher frequencies. Therefore, the production of new equipment should always use a high-frequency substrate, satellite system, mobile receiving base station, and so on. These communication devices must use high-frequency PCB.
Characteristics of high-frequency PCB
- DK should be small and stable enough; usually a little better, higher DK can cause a delay in signal transmission.
- The DF should be small, the more damaging the signal flow type, the smaller the DF can produce a signal deficit.
- The increase in temperature should be as high as the copper foil as much as possible because the difference will lead to the copper foil separating in temperature and temperature changes.
- Water intake should be low, the high water content will affect DK and DF if it is in a humid environment.
- Heat unprotected heat, chemical resistance, corrosion resistance, and corrosion strength should be good.
Tools used on HF circuit boards.
High-frequency board wireless applications and data receivers in the high GHz range have special requirements for applications:
- Adaptive permittivity.
- Lower reduction of active signal movement.
- Homogeneous build-up and low tolerance in the protective and dielectric coating at all times.
Generally speaking, high frequency can be defined as a frequency over 1GHz. At present, CAMTECH PCB widely uses PTFE material to produce high-performance PCB, whose frequency is usually more than 5GHz., FR4 or PPO substrate can be applied to the product frequency between 1GHz and~10GHz. These three high-frequency substrates have the following differences:
In terms of the price of FR4, PPO, and Teflon laminate, FR4 is the cheapest, while Teflon is the most expensive. When it comes to DK, DF, fluid density, and frequency function, Teflon is the best. If the operating system requires a frequency above 10GHz, we can only select the Teflon PCB substrate design. Teflon performance is better than other substrates. Thus, Teflon substrate has the advantage of high cost and high heat dissipation structure. To improve PTFE strength and heat protection equipment function, a lot of SiO2 or glass fiber as a filling material. On the other hand, due to the inertness of the PTFE material molecule, which is not easy to mix with copper foil, a High-value treatment is required on the joint. For high therapeutic combinations, usually use chemical etching over the PTFE surface or plasma etching to increase surface hardness or increase the adhesive film between PTFE and copper, but this may affect dielectric performance.
PCB vias can impair signal integrity
PCB Vias – Under normal circumstances, you need to move the post so that the return is now passing through the bottom plane, which is directly below the line, well. It also occurs in an equally controlled impedance for moving the cable. However, if the PCB Vias gets in the way, the return now must find a way to change itself. You will have to cross the cells and go to the area with the nearest deep PCB vias.
Therefore, if the return current closes any other distance, it slows the high-frequency signal. It is due to the design of the inductive loop due to the increased PCB method. Not only that; and it can also collect unwanted signals in this way. In addition, PCB vias also impair signal reliability due to long delays and significant rise and fall time. You can learn the S-parameters to check the course patterns on the reliability indicator. They show the characteristics of all channel components, including errors, attenuation and reflection, and more.
To improve signal reliability, protect your PCB by reading up to a minimum when there are high frequency pcb signals. You will find faster departure times and shorter delay times. If you add small PCB vias, they can give you a shorter delay, but they do not affect the rise time much longer. Lastly, you can also make a wish to reduce the length of your PCB vias. It also leads to faster rise time and slower delays.
