Suitable inductor design of the radio frequency circuit

25 This article introduces the non-mational behavior of high frequency inductance and helps you choose a suitable capacitance and inductor for use in a network, DC module, crystal, and power supply. In addition to inductance, the inductor also includes parasitic capacitance and parasitic resistance. The figure below describes a model of a real inductor. RDC is an ohmic resistance because the electrical conductivity of inductance is limited. The RAC is a frequency-dependent resistance representing the inductive magnetic core loss. The parasitic capacitor is the result of the capacitance between the inductor coil. RAC is very high at low frequencies, usually ignored. The effective impedance of the inductor is Parasitic capacitors have very high impedance at low frequencies, which is small for overall impedance because it is parallel to inductance. As the frequency increases, the impedance generated by the capacitance (XCP) is reduced, and the impedance generated by the inductor (XL) is increased. XL and XCP ultimately becomes equal at a certain frequency. This frequency is the self-resonant frequency (SRF) of the inductor. Since the RDC is usually very low, the inductor appears as an open or high impedance at this frequency. The inductor used in the matching network (very important) should have a SRF much higher than the operating frequency. When the inductor is used for power filtering, the inductance value selected by the SRF is close to the noise frequency is a wise choice. The quality factor of inductor The quality factor (q) of the inductor (L) is the ratio of the reactance of the inductor in a given frequency (f) and its resistance (R). Make sure the Q factor of Q factors used in matching networks is important. The low Q value has a large impedance. When using a low Q component, in the matching network, even if the impedance matches are not good, it is possible to mislead S11 because most of the energy is not transferred to the load, but is wasted as heat in the resistor. Inductors recommended ▪ For matching network, only SRF is much higher than the high Q inductance of operating frequency. ▪ For power filtering, use SRF to close the inductance of the noise frequency. ▪ Do not place the inductance parallel and close to each other. Mutual mottle between them cause crosstalk. Let the inductor or unrelated part of each other. ▪ RF ceramic inductor has high cost, high SRF, but Q and current capacity is lower, especially for inductors with higher values. ▪ The winding inductor has a lower DC resistance, so there is a high Q and current capacity. For high value inductors, the wireback inductor is preferably used in ceramic inductors.

Our other product:

Professional lightning protection system for Tower	Professional FM Radio Station Equipment Package	FMUSER FU-1000C 1000W FM Transmitter With USB Audio Input Interface
FMUSER 200W FM Radio Broadcasting Package	Hotel IPTV Solution	FMUSER FSN-1000T V5.0 1KW FM Radio Broadcast Transmitter