PCB News - pcb factory: how to choose the circuit materials of the power divider and coupler

PCB factory: how to choose the circuit materials of the power divider and coupler

PCB factory: Power splitter and combiner are the most commonly used\most common high-frequency components, and the same is true for couplers such as directional couplers. These components are used to divide, combine, and couple high-frequency energy from the receiving antenna or the system, and the damage and leakage are small. The selection of PCB material is a key factor for the successful realization of the expected performance of these components. When presetting and processing the power splitter/combiner/coupler, it is very beneficial to understand how the properties of the PCB material affect the final performance of these components, for example: it can help a series of different materials selected Performance indicators are limited, covering the frequency range, office bandwidth, and power capacity.

Many different circuits are used for preset power dividers (in turn, combiners) and couplers, and they have various different methods. The power divider has a simple dual-channel power divider and a complex N-channel power divider. N depends on the actual needs of the system. Many different directional couplers and other types of couplers have also made great progress in recent years, including Wilkinson and resistive power splitters, Lange couplers and quadrature hybrid power-saving bridges. They have many different Way and size. Choosing appropriate PCB materials in these circuit presets helps them achieve the best performance. These different circuit types will compromise the structure and performance of the problem preset, and help the presetter choose the sheet material for different applications. The Wilkinson dual power divider is a pure one input signal to supply dual output signals of equal amplitude and phase. In fact, it is a "lossless" circuit. It is preset to provide a phase that is smaller than the original signal. 3dB (or half of the original signal) output signal (the output power of each port of the power divider decreases as the number of output ports increases). In terms of phase, the resistive two-way power divider provides an output signal that is 6dB smaller than the original signal. The increased impedance of each branch in the resistive power divider increases the damage, but also increases the isolation between the two signals.

Like many circuit presets, the dielectric constant (Dk) is generally the starting point for choosing different PCB materials, and the presets of power dividers/power combiners generally tend to use high dielectric constants ( Dk) circuit materials, because these materials are in phase with low-dielectric constant materials, they can be used for electromagnetic coupling in smaller-sized circuits. There is a problem with circuits with high dielectric constants, that is, the dielectric constant in the circuit board is anisotropic or the dielectric constants of the board material are different on the x, y, and z sides. When the dielectric constant of the same direction varies greatly, it is also difficult to obtain a transmission line with uniform impedance.

Maintaining the impedance without changing the gender is very important when successfully realizing the special properties of the power splitter/combiner. The change of the dielectric constant (impedance) will cause the electromagnetic force and the warped edges of the power distribution. Fortunately, there are economically active PCB materials with excellent isotropy that can be used in these circuits, such as TMM? 10i circuit materials from Rogers Corporation. These materials have a relatively high dielectric constant of 9.8, and are maintained at a level of 9.8+/-0.245 on the three coordinate axes (surveyed at 10GHz). It can also be understood that, in the transmission line of the power splitter/combiner and the coupler, the uniform impedance and special properties can make the distribution of the electromagnetic force + the component contact eternally fixed and measurable. For higher dielectric constant PCB materials, the TMM 13i laminate has a dielectric constant of 12.85 and the variation in the three axes is within +/-0.35 (10GHz). Of course, when presetting the power divider/power combiner and the coupler, the eternally fixed dielectric constant and the special characteristics of the impedance are only one of the parameters of the PCB material that needs to be considered.

When the power splitter/combiner or coupler circuit is preset, it is generally a key goal to minimize the damage caused by the insertion. Under ideal conditions, a dual-channel Wilkinson power splitter can provide two The output port is -3dB or one-half of the input electromagnetic force + ray. In fact, each power splitter/combiner (and coupler) circuit will have a certain amount of insertion to remove damage, which generally depends on the frequency (when the frequency increases, the damage also increases), so for a power divider/ The default of the combiner, the selection of PCB materials requires consideration of how to control the problem, and the insertion of the circuit requires minimal damage. In passive high-frequency components such as power splitters/combiners or couplers, the insertion and removal of damage is actually the whole of many damages, including medium damage, conductor damage, radiation damage and leakage damage. Some of the damage inside can be controlled by dedicated circuit presets. They may also rely on the special properties of PCB materials and the PCB materials can be selected reasonably to minimize damage. Rogers Corporation’s PCB material leakage damage is minimized. For example, when making a transmission line, Rogers’ sheet material has a high volume resistivity, so high isolation is provided to reduce leakage damage. Improper impedance matching (ie, standing wave ratio damage) can cause damage, but it can be reduced by selecting PCB materials with a permanent dielectric constant.

Minimizing the damage is very important in the power divider/combiner and coupler with a preset high power value. Because the damage will be converted into calories and dissipated in the components and PCB materials at high power, and the calories will affect the materials. The dielectric constant number (and impedance value) of the initiation influence. In short, when presetting and processing high-frequency power splitters/combiners and couplers, the selection of PCB materials should be based on the special properties of many different key materials, covering the constant number of dielectric constants, the continuity of the dielectric constant of the material, and the background Factors such as temperature, reducing material damage covers media damage, conductor damage and power volume. The selection of PCB board materials for specific applications helps to achieve success when presetting high-frequency power splitters/combiners or couplers.