RF passive device overview
RF passive devices are divided into three categories: power distribution devices, microwave resonant devices, and connection matching components. Power distribution devices are divided into three categories: 1. Power splitters (microstrips, cavities) 2. Couplers (microstrips, cavities) 3. Microwave splitters; Microwave resonators: 1. Filter 2. Double Tools 3. Combiner; connection matching components: 1. Terminal load 2. Attenuator 3. Impedance matching component. The terminal load is divided into three small blocks, which are short-circuit load, mismatch load, and matched load (coaxial matching load, microstrip matching load).
Power splitter for RF passive devices: Definition: A power splitter is a device that divides the energy of one input signal into two or more output powers. It can also conversely synthesize multiple signal powers into one output, one power point. There should be a certain degree of isolation between the output ports of the device. Product categories: 800MHz-2500MHz wide-band cavity power splitter, 698MHz-2700MHz broadband high-power cavity power splitter, and 800MHz-2500MHz broadband microstrip power splitter. Typical indicator: Broadband cavity splitter RD-52(3,4)N/NP-32. Parameter description of electrical parameters: Insertion loss: The device's direct loss, which is calculated as the ratio of the sum of the output power of all the channels to the input power, or the actual direct loss of a single channel minus the ideal distribution loss. The general ideal distribution loss is as follows Way to get: Ideal distribution loss (dB) = 10log(1/N) N is the number of splitters
Isolation:When the main circuit is connected to the matching load, the opposite ends of the output ports are isolated. Amplitude balance: The maximum amplitude error between all output ports in the band. Standing wave ratio: refers to the ratio between the maximum value of the voltage along the direction of signal transmission and the minimum value of the adjacent voltage.
Cavity splitter and microstrip splitter:
Couplers for RF Passive Components: Directional Coupler Definitions: Directional couplers are often used to sample a specified stream of microwave signals. In the absence of load, directional couplers are generally a four-port network. Product classification: Base station high power coupler, 800MHz-2500MHz cavity directional coupler and 800MHz-2500MHz coaxial cavity coupler. Typical Specifications: Broadband cavity directional coupler RC-5NK-xxF3. Electrical Specifications Parameter Description: Coupling: When the other ports are connected to the matching load, the ratio of the output power of the coupling to the input power of the main line. Coupling loss: Since the output power of the main line is reduced due to the transmission of certain energy to the coupling end, it is equal to the theoretical value of main line insertion loss. The relationship between the minimum theoretical value and the coupling degree is as follows:
Electrical parameter parameter description: Isolation: When the input termination matches the load, the isolation between the output port and the coupling port. Directionality: The difference between the output power of the coupled port and the output power of the same coupled port when the same power is transmitted in the opposite direction when the power is transmitted in the direction of development.
Directionality = isolation - coupling
RF Passive Devices - Couplers: Cavity Couplers vs. Microstrip Couplers:
Filters for RF Passive Components: Definition: A filter is a two-port network whose basic application is to suppress undesired frequency signals so that the desired signal passes through the frequency system in the microwave system. The filter is mainly used as a module-level product to support the use of the main equipment. In some cases, the need to overcome clutter interference outside the frequency band can be used alone. In real life, combining two or more filters together becomes a duplexer, also known as a combiner. Typical indicator: Filter FC-8C190117SB301. Product Category: Low-pass filter, high-pass filter, band-pass filter and band-stop filter. Structure: It is composed of tuning rod, cover plate, joint, resonant column and cavity. Parameters of electrical parameters: Main parameters include passband frequency, passband bandwidth, insertion loss, in-band fluctuation, return loss, etc. There is a certain link between each index. They are not independent.
RF combiner of RF passive components: Introduction: Combiners are divided into two types, which are the same frequency combiner and the different frequency combiner. Off-band combiners are used to synthesize the signal power of two different frequency bands. Definition: A band combiner is a unit composed of multiple filters. It is a multi-port network where all ports are input/output dual-function ports. Typical indicator: Dual-frequency combiner CM-2WNN1D01.
RF passive components - combiner: combiner VS splitter
Attenuators for RF Passive Components: Definition: Coaxial attenuators are commonly used in engineering and consist of "π" or "T" attenuation networks. Coaxial attenuators usually have fixed and variable attenuation. It is mainly used to control microwave signal transmission energy and consume excess energy, thus expanding the dynamic range of signal measurement, such as amplifiers, spectrum analyzers, receivers and so on. Product classification: According to the different degree of attenuation, it is classified with the power capacity. Attenuator Typical Specifications: Attenuator TSEXX-XXdB. A typical indicator of the load of a passive device: load LD-XXNJE.