GP antennas is short for GroundPlaneAntenna. These antennas are with a ground plane. Their elements are usually mounted by vertical ground, so they are also called vertical GP antennas. The antennas has a low emission inclination, and its coverage is similar to a circle with the radius of the emission point, so it is indispensable as a simple and effective DX weapon. The disadvantage is that it is a little noisy.
What parts make up the vertical GP antenna?
The structure of vertical GP antenna is relatively simple, mainly including the main element (generally add external main beam to protect the main element), cables of ground network, sometimes added balun or choke coil formed by the coaxial cable winding and so on. The main beam is generally made of PVC and other insulating materials, and it is required to be thicker than the antenna main element tube to protect the main element from rain and other damage; the main element can be common conductors such as aluminum tubes, stainless steel tubes, and stainless steel rods; for ground cables, you can choose copper core wire for general lighting, 8-core flat wire, 80-row IDE hard disk data cable, etc. Generally speaking, all materials of GP antennas are easy to obtain and have simple working principles.
What's the radiation principle of vertical GP antenna?
The GP antenna is generally fed by a coaxial cable, the inner conductor is connected to the vibrator, and the outer conductor is grounded. A choke coil formed by balun or coaxial cable winding is added to choke the effect of common mode current. As shown in the above figure, when the 1/4λ main element is erected vertically on the ground, the maximum radiation direction can be as close as possible to the height of the radio placement, and the best radiation effect has been achieved.