Sichuan Keenlion Microwave Technology——Passive devices
Sichuan Keenlion Microwave Technology Founded in 2004, Sichuan Keenlion Mircrowave techenology CO., Ltd. is the leading manufacturer of the Passive Mircrowave components in Sichuan Chengdu, China.
We provide high-performance mirrowave components and related services for microwave applications at home and abroad. The products are cost-effective, including various power divider, directional couplers, filters, combiners, duplexers, customized passive components, isolators and circulators. Our products are specially designed for various extreme environments and temperatures. Specifications can be formulated according to customer requirements and are applicable to all standard and popular frequency bands with various bandwidths from DC to 50GHz.
Passive devices are an important class of microwave and RF devices, which play a very important role in microwave technology. Passive components mainly include resistors, capacitors, inductors, converters, gradients, matching networks, resonators, filters, mixers and switches.
Passive components mainly include resistors, capacitors, inductors, converters, gradients, matching networks, resonators, filters, mixers and switches. An electronic component that can display its characteristics without external power supply. Passive components are mainly resistive, inductive and capacitive devices. Their common feature is that they can work when there is a signal without adding power in the circuit.
When a current passes through a conductor, the property that the internal resistance of the conductor hinders the current is called resistance. The components that play the role of blocking current in the circuit are called resistors, which are referred to as resistors for short. The main purpose of resistor is to reduce voltage, divide voltage or shunt. It is used as load, feedback, coupling, isolation, etc. in some special circuits.
The symbol of resistance in the circuit diagram is the letter R. The standard unit of resistance is Ohm, which is recorded as Ω. Commonly used are kiloohm KΩ and megaohm mΩ.
Capacitor is also one of the most common components in electronic circuits. It is a component for storing electric energy. The capacitor is composed of two conductors of the same size and quality sandwiched with a layer of insulating medium. When a voltage is applied to both ends of the capacitor, an electric charge is stored on the capacitor. Once there is no voltage, as long as there is a closed circuit, it will release electric energy. The capacitor prevents DC from passing through the circuit and allows AC to pass through. The higher the frequency of AC, the stronger the passing ability. Therefore, capacitors are often used in circuits for coupling, bypass filtering, feedback, timing and oscillation.
The letter code of capacitor is C. The unit of capacitance is farad (recorded as f), which is commonly used μF (micro method), PF (i.e μμF. Pico method).
The characteristics of capacitance in the circuit are nonlinear. The impedance to current is called capacitive reactance. Capacitive reactance is inversely proportional to capacitance and signal frequency.
Like capacitance, inductance is also an energy storage component. Inductors are generally made of coils. When AC voltage is applied at both ends of the coil, induced electromotive force is generated in the coil, which prevents the current passing through the coil from changing. This hindrance is called inductive resistance. The inductive reactance is directly proportional to the inductance and the frequency of the signal. It does not hinder the DC current (regardless of the DC resistance of the coil). Therefore, the role of inductance in electronic circuits is: current blocking, voltage transformation, coupling and matching with capacitance for tuning, filtering, frequency selection, frequency division, etc.
The code of inductance in the circuit is L. The unit of inductance is Henry (recorded as H), and the commonly used ones are milliheng (MH) and micro Heng（μH)。
Inductance is a typical component of electromagnetic induction and electromagnetic conversion. The most common application is transformer.
1. Integrated modularization is the future development trend of passive components. The integration module provides the ability to integrate active components or modules and passive components, and meets the requirements of module reduction and low cost at the same time. The main methods include: low temperature co fired ceramic technology (LTCC), thin film technology, silicon wafer semiconductor technology, multilayer circuit board technology, etc.
2. Miniaturization. The pursuit of miniaturization and lightweight in the wireless industry requires passive devices to develop in a smaller direction. Micro electro mechanical system (MEMS) is mainly used to make RF components smaller, lower cost, more powerful and more conducive to integration.
3. Encapsulation effect. Compared with the commonly used surface mounted passive components, the integration of components into the package can effectively improve the reliability of the system, shorten the conductive path, reduce parasitic effects, reduce costs and reduce the size of devices.
Differences between active and passive components
Passive devices are devices that can show their external characteristics independently without the existence of external power supply (DC or AC). Besides, there are active devices. The so-called “external characteristic” is to describe a certain relationship quantity of the device, although the voltage or current, electric field or magnetic field, pressure or speed and other quantities are used to describe its relationship.
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Post time: Mar-14-2022