Main lobe width
It is defined as the width of the gain decreasing by 3 decibels relative to the maximum gain in the directional graph, in units of degree (radian).

Sidelobe level
The ratio of the maximum of the side lobe to the maximum of the main lobe is called the side lobe level, which is generally expressed in decibels and is defined as 101g (maximum power of the side lobe/maximum power of the main lobe).
For example, the ratio of the maximum power of the side lobe to the maximum power of the main lobe is 0.01, and the side lobe level is -20dB.

Polarization mode
The polarization forms of electromagnetic wave can be divided into linear polarization wave and circular polarization wave. Linear polarization wave can also be divided into horizontal polarization wave and vertical polarization wave. Circular polarization wave can be divided into left-handed and right-handed circular polarization wave according to the rotation direction of electric field.

VSWR
Voltage standing wave ratio (VSWR) is used to describe the matching performance of ports. The same performance can also be expressed by echo loss. These two indicators are defined as follows.

VSWR:
VSWR=(1+ | R |)/(1-| R |) r: For emission coefficient = ZL-Z0/ZL+Z0 ZL as input impedance, Z0 as ideal impedance

Echo loss:
RL = 10log (incident power / reflective power) 

dynamic range
Refers to the maximum and minimum power range allowed by the input signal. The lower limit is limited by the noise performance of the amplifier, and the upper limit depends on the non-linear index.