The working principle and function of wireless transmitting and receiving module

The wireless transmitting and receiving module is engaged in digital audio wireless transmission, wireless data communication, wireless transmission system, wireless remote control and telemetry system, wireless data acquisition system, wireless network, wireless security system, etc., wireless transceiver circuit design has always been a bottleneck in wireless applications. The wireless transceiver module integrates the functions of the high-frequency key-control transceiver circuit to realize high-speed data transmission with a small size and lower cost. The following explains the working principle and function of the wireless transmitting and receiving module.

The receiving module corresponding to the wireless transmitting module is commonly used in two types: super-regeneration receiving and super-heterodyne receiving.

1. Super Regenerative Detection Receiver

The super regenerative detection circuit is actually a high frequency oscillator controlled by intermittent oscillation.?This high frequency oscillator uses a three-point capacitor oscillator, and the oscillation frequency is consistent with the emission frequency of the transmitter. The intermittent oscillation is generated during the oscillation of the high-frequency oscillation, which in turn controls the oscillation and the pause of the high-frequency oscillator.?The frequency of the intermittent oscillation is determined by the parameters of the circuit (generally from one hundred to several hundred kilohertz). This frequency is selected low, the circuit has better anti-interference performance, but the receiving sensitivity is lower. Conversely, the frequency is selected higher, the receiving sensitivity is better, but the anti-interference performance is worse. The super-regenerative detection circuit has a high gain. When the clamp signal is not received, due to the interference of external spurious signals and the thermal disturbance of the circuit itself, a unique noise is generated, called super noise, and the frequency range of this noise. It is between 0.3 and 5 kHz, which sounds like a “sand” sound like water. When there is no signal, the super noise level is very high, and the noise voltage is output after filtering and amplification; when a clamp signal arrives, the circuit resonates, super noise is suppressed, and the high frequency oscillator starts to generate oscillation and output signals.

2. Superheterodyne Receiving Detection Receiver

The principle of the superheterodyne receiving circuit is the same as that of the general superheterodyne radio. It amplifies the received signal and subtracts it from the equal-amplitude oscillating signal generated by the unit to generate a fixed-frequency IF signal. The amplitude of the IF signal includes a low-frequency modulated clamp signal, and the IF signal is added. Two-stage or three-stage amplification, and then detection, the low-frequency command information contained in the intermediate frequency signal is taken out, and the correct remote signal is obtained. Since the IF amplifier is equipped with an automatic gain clamp loop, its gain can be designed to be very high and the operation is very regulated, which makes the superheterodyne receiver basically the same for both strong and weak signals. Magnification, also because of the use of the IF amplifier, its signal amplification can be very large, which makes the receiving sensitivity of the circuit greatly improved, generally up to 0.1mV. Compared with the super-regenerative detection circuit, the super-heterodyne receiver module has a great improvement in both receiving sensitivity and selectivity, and is more significant in anti-jamming.

The three functions of the wireless transmitting and receiving module:

Function 1. A wireless communication network used to form a star topology. And it must be a multi-point star topology, and some extraordinary places require wireless communication. On the one hand, such a wireless transmitting and receiving module is inexpensive, and the cost of forming a star topology is relatively low; on the other hand, the wireless transmitting and receiving module can be modularized, small in size, easy to use, and easy to integrate. This kind of wireless transmitting and receiving module is very practical for wireless networks with low communication speed and close distance.

Function 2. For wireless multi-channel (parallel) control. For example, complex remote control robots require multi-channel (parallel) control in some locations. One method is to directly connect the decoder to the decoder, and then connect with the electronic components such as the relay to drive the subsequent controlled object; the other method is to connect the wireless receiving module and the single chip microcomputer, and then use the data after disposal. The MCU connects the electronic components such as relays to drive the subsequent controlled objects. Usually, a pair of wireless transmitting and receiving module can realize up to six parallel wireless control. If the required number of channels is greater than six, multiple pairs of transmitting and receiving modules can be used to work simultaneously to meet actual needs.

Function 3. For general-purpose serial port (RS232) wireless data transmission. There are usually many control instruments and equipment using serial port, and communication with these devices must meet the serial port requirements. Some extraordinary places, industrial control site. When it is necessary to use the wireless transmission method, it is natural to select the wireless transmitting and receiving module mentioned in this article.However, in this case, the communication method must be used. It is necessary to separately compile the corresponding software implementation file format at the transmitting end and the receiving end to achieve wireless communication. Purpose, if the communication system is full-duplex, it can be implemented by using two pairs of shooting and receiving modules.

The above is about the working principle and function of the wireless transmitting and receiving module, and it is hoped that it will be helpful to friends who need the wireless transmitting and receiving module.?Yaoertai?Technology focuses on wireless transmitting and receiving modules and sensor applications. The wireless transmitting and receiving module feature long range and high stability.