Power supply, load, and transmission lines can be divided into two categories based on their relationship with ground: balanced and unbalanced. If the voltage between the two ends of the power supply and the ground is equal and the polarity is opposite, it is called a balanced power supply; otherwise, it is called an unbalanced power supply; Similarly, if the impedance between the two ends of the load or the two conductors of the transmission line and the ground is the same, it is called a balanced load or balanced (feeder) transmission line; otherwise, it is called an unbalanced load or unbalanced (feeder) transmission line.

　　Coaxial cables should be used to connect between unbalanced power sources or loads, and parallel (feeder) transmission lines should be used to connect between balanced power sources and loads in order to effectively transmit electromagnetic energy. Otherwise, their balance or imbalance will be disrupted and cannot function properly. To solve this problem, a "balanced unbalanced" conversion device is usually installed in the middle, commonly known as a balanced converter.

　　1. A half wavelength balancer, also known as a U-shaped balanced converter, is used for balancing transformation when connecting unbalanced feeders to balanced loads, and has an impedance transformation effect.

　　In mobile communication systems, coaxial cables typically have a characteristic impedance of 50 ohms, so it is necessary to adjust the impedance of the folded half wave oscillator antenna to around 200 ohms using appropriately spaced oscillators in order to achieve the final impedance matching with the 50 ohm coaxial cable of the main feeder.

　　2. Quarter wavelength balanced - unbalanced. Utilizing the property of a quarter wave long and short transmission line terminal being a high-frequency open circuit to achieve a balance imbalance transformation between the antenna balanced input port and the coaxial feed line unbalanced output port

Read recommendations:

isolator circulator

rf band pass filter

rf isolator

wideband rf circulator.RF attenuator radar system

rf power splitter combiner.How to purchase RF admittance level switches?