1. Power/level (dBm): the output capability of the amplifier, generally in units of w, mw, dBm
Note: dBm is the absolute power level expressed in decibels by taking 1mw as the reference value. Conversion formula:
5W → 10lg5000=37dBm
10W → 10lg10000=40dBm
20W → 10lg20000=43dBm
It is not difficult to see from the above that each time the power is doubled, the level value increases by 3dBm
2. Gain (dB): the magnification, the unit can be expressed as decibel (dB).
That is: dB=10lgA (A is the power amplification factor)
3. Insertion loss: The attenuation added when a device or component is connected to the transmission circuit, expressed in dB.
4. Selectivity: measure the gain in the working frequency band and the suppression ability of out-of-band radiation. The -3dB bandwidth is the bandwidth when the gain drops by 3dB, and the same is true for -40dB and -60dB.
5. Standing wave ratio (return loss): the ratio of the antinode voltage to the node voltage (VSWR) in the standing wave state
6. Third-order intermodulation: If there are two sinusoidal signals ω1 and ω2, many intermodulation components will be generated due to nonlinear effects. The two frequency components of 2ω1-ω2 and 2ω2-ω1 are called third-order intermodulation components, and their power The ratio of P3 to the power of the signal ω1 or ω2 is called the third-order intermodulation coefficient M3.
7. Noise figure: generally defined as the ratio of the output signal-to-noise ratio to the input signal-to-noise ratio, which is calculated in decibels in actual use. The unit is dB.
8. Coupling: the power ratio between the coupling port and the input port, in dB.
9. Isolation: the ratio of the power of the local oscillator or signal leaked to other ports to the original power, in dB.
10. Antenna gain (dB): refers to the ability of the antenna to concentrate the transmit power in a specified direction. Generally, the field strength E in the maximum radiation direction of the antenna is compared with the uniform radiation field strength E0 of the ideal isotropic antenna, and the gain is defined as the multiple of the power density increase. Ga=E2/ E02
11. Antenna pattern: It is the range of electromagnetic waves radiated by the antenna in free space. The width of the pattern generally refers to the width of the main lobe, that is, the angle between the two points when the width is reduced by half from the maximum value.
The E-plane pattern refers to the radiation pattern in the plane parallel to the electric field;
The H-plane pattern refers to the radiation pattern in the plane parallel to the magnetic field.
Generally, the wider the pattern, the lower the gain; the narrower the pattern, the higher the gain.
12. Antenna front-to-back ratio: refers to the ratio of the maximum forward gain to the maximum reverse gain, expressed in decibels.
13. Simplex: Also known as single-frequency simplex system, that is, the same frequency is used for sending and receiving. Since the same frequency is used for receiving and sending, the sending and receiving cannot be performed at the same time, which is called simplex.
14. Duplex: Also known as different frequency duplex system, that is, two different frequencies are used for sending and receiving, and either party can receive the other party's speech while speaking.
Simplex and duplex are the working methods of mobile communication.
15. Amplifier: (amplifier) circuit used to achieve signal amplification.
16. Filter: (filter) A component or device that suppresses useless frequency signals through useful frequency signals
17. Attenuator: (attenuator) A four-terminal network composed of resistive elements with zero phase shift, its attenuation and characteristic impedance are constants independent of frequency in a fairly wide frequency range, and its main purpose is to adjust Signal size in the circuit, improve impedance matching.
Power divider: A device that divides power. There are two, three, four.... power dividers; the connector types are divided into three types: N head (50Ω), SMA head (50Ω), and F head (75Ω). Our company commonly uses N head and SMA head.
18. Coupler: A device that extracts part of the signal from the main channel. According to the degree of coupling, it is divided into 5, 10, 15, 20.... dB different specifications; high-power couplers (300W) can be used to extract signals from the base station, and the coupling degree can be selected from 30~65dB; the connectors of the couplers are mostly N head.
19. Load: The terminal in a circuit (such as an amplifier) or an electrical output port, the components/devices, components or devices that receive electrical power are collectively referred to as loads. The most basic requirements for the load are impedance matching and the power it can withstand.
20. Circulator: A device that transmits signals in one direction.
21. Adapter: A device that connects different types of transmission lines together.
22. Feeder: It is a transmission line that transmits high-frequency current.
23. Antenna: (antenna) converts high-frequency current or energy in the form of waveguide into electromagnetic waves and emits them in a specified direction or restores electromagnetic waves from a certain direction to high-frequency current.
That is, M3 =10lg P3/P1 (dBc)