What is an ESC antenna and the application of AISG in it?
What is an ESC antenna and the application of AISG in it?
AISG ESC Antenna Cable
RET Remote Electrical tiling
RCU Remote Control Unit
CCU Central Control Unit
1. Mechanical antenna and ESC antenna
Mechanical downtilt refers to directly adjusting the physical tilt angle of the antenna to change the beam coverage.
Electronic downtilt refers to changing the beam coverage by changing the phase of the antenna element without changing the physical position of the antenna; generally, ESC antennas are capable of remote control.
1.1 Principle of ESC Antenna Adjustment
The coverage of the antenna is achieved by the vertical main beam, and the adjustment of the downtilt angle changes the main beam coverage. For electronically regulated antennas, the phase shifter is used to change the phase of the power signal obtained by each radiating element (vibrator) in the antenna array to realize the downtilt of the vertical main beam, which is the application of radar phased array technology in mobile communications.
ESC antennas generally adjust the oscillator circuit on the physical structure of the motor to realize the change of the oscillator path; this is the phase shifter, which changes the feeding phase of each oscillator by adjusting the length of the feeding network to realize the downtilt of the antenna beam.
The ESC antenna RET (Remote Electrical Tilt) is composed of the antenna and the Remote Control Unit (RCU). The reason why the ESC antenna can achieve continuously adjustable electrical downtilt is the use of mechanically adjustable inside the antenna. The multi-channel phase shifter, the device has one input and multiple outputs, and the phase of each output signal can be changed at the same time through the mechanical transmission mechanism (change the oscillator path). The remote control is then performed by the remote control unit RCU.
Phase shifters can be simply divided into two types: moving transmission lines and moving media; the difference is that when the motor rotates, it adjusts the length of the transmission line or adjusts the position of the medium.
RCU consists of drive motor, control circuit and transmission mechanism. The transmission motor generally adopts a numerically controlled stepping motor. The main function of the control circuit is to communicate with the controller and control the driving motor. The driving structure mainly includes a gear, which can be engaged with the transmission rod. When the gear rotates under the drive of the motor, it can be pulled. Drive the rod, thereby changing the downtilt angle of the antenna.
RCU is divided into external RCU and built-in RCU:
- The RET antenna with built-in RCU means that the RCU has been installed on the antenna and shares the same housing with the antenna.
- RET antenna with external RCU means that the RCU controller needs to install an RCU between the corresponding ESC interface of the antenna and the ESC line, and the RCU is outside the antenna mask.
The external RCU can clearly understand its structure. The external RCU will be introduced in detail below. In simple terms, RCU can be understood as a remote controllable motor, one input control signal and the other output motor drive.
The RET interface is the interface for connecting the AISG control line. Generally, the built-in RCU only provides this interface for connecting to the RRU.
The interface between the RCU and the antenna, the white part in the figure below is the motor drive shaft, which is connected to the antenna
It can be clearly seen that the RCU directly drives the motor to control the internal phase shifter of the antenna, rather than controlling the phase shifter through the signal line; the RCU and the antenna interface are mechanical transmission structures, not signal line structures.
External RCU antenna interface
2.4 AISG cable
For the built-in RCU, because it is integrated inside the antenna mask, it is enough to directly connect the electrical adjustment line between the antenna (actually the internal RCU) and the RRU. Regardless of the built-in RCU or the external RCU, it is connected to the RRU through the AISG control line.
AISG (antenna interface standards group) is an organization for antenna interface standards, the website is: http://www.aisg.org.uk/, mainly used for remote control of base station antennas and tower amplifiers
AISG includes interface specifications and protocols, and defines the standards and communication processes of related interface communication
The base station control signal and DC signal are transmitted to the RCU through the AISG multi-core cable. The master device can remotely control one RCU, and can also control and manage multiple cascaded RCUs.
The base station modulates the control signal into a 2.176MHz OOK signal (baiOn-Off Keying, binary amplitude keying, which is a special case of ASK modulation) through an external or built-in BT, and transmits it to the SBT through an RF coaxial cable together with the DC signal, which is SBT completes the mutual conversion between OOK signal and RS485 signal.
3.2 Remote ESC Mode
The remote ESC is shown in the figure below. The basic method is to control the ESC through the base station network management. The control information is sent to the base station through the base station network management, and the base station transmits the control signal to the RCU. modulation.
The difference between the left and right sides lies in the way the base station transmits the control signal to the RCU.
Premier Cable make a lot of AISG 2.0 Cable & AISG ESC Antenna Cable
You can see the products details from below link , https://www.premier-cable.net/product/AISG-Cables-6
If you need product details, drawings, and samples, you can use below contact info :
Skype : James198585
Wechat : 13929497934