What Is a 900 MHz Wireless Transmitter?

Infrared wireless microphone, that is, infrared wireless microphone, uses infrared light as a carrier of sound signals to implement a wireless amplification system for transmitting and receiving. The basic principle is similar to ordinary radio frequency systems. In the process of wireless transmission and reception, the process of modulation and demodulation of sound signals is also required. However, the carrier of infrared wireless microphones is infrared light, and its frequency is much higher than that of ordinary wireless systems. The infrared wireless microphone module determines that the frequency of ordinary wireless microphones is 200-900MHz, which is commonly referred to as radio frequency (frequency bands used by radio stations, television stations, and wireless communications); the frequency of infrared microphones is above 3G, and the frequency environment is clean, with few equipment Radiating interference waves.

Infrared wireless microphone

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Although the infrared light is invisible, it has all the characteristics of light waves: straight-line propagation, very strong reflection performance; diffraction ability and penetrating power are very weak. When the infrared microphone works, it needs a basic reflecting surface, otherwise the signal receiving window will not be able to receive the signal. So infrared

1. Do infrared microphones interfere with each other?

Infrared rays are transmitted in a straight line, so infrared wireless microphones in each relatively independent space will not interfere with each other. However, if infrared microphones of the same frequency are placed in the same space, they will not work properly due to mutual interference. At present, infrared microphones generally have two independent distinguishing frequencies, namely A and B channels (there are obvious distinctions at the transmitting end). An infrared receiving host can simultaneously receive signals from one microphone of each of the A and B channels, but it cannot accept Two or more A channels; two or more B channels.

2. Since the infrared microphone uses infrared light as a carrier wave, will there be a break due to the movement of people in the space or the movement of the transmitting end?

The light has very strong reflection performance, and the optical signal sent from the transmitting end does not need to reach the receiving end directly, but as long as the optical signal reflected and scattered by the reflecting surface reaches the receiving window, it can ensure reliable reception. At present, infrared microphones use multi-point transmission and multi-point reception technology to further ensure the reliability of reception. The infrared signals emitted by the transmitting end in various directions in space will be reflected in various reflective surfaces and scattered, and will be in a relatively sealed space A dense, invisible light network without blind spots is formed inside. At the same time, the receiving window is also expandable. Increasing the number of receiving windows and selecting a suitable installation location can increase the receiving reliability coefficient and increase the receiving radius. Therefore, the infrared microphone will not be interrupted due to the movement of people in the space or the movement of the transmitting end.

3 Will the infrared microphone be interfered by the light from fluorescent lamps, electric lamps and other lighting equipment?

In the design of the infrared microphone, the selected infrared light band has avoided the infrared light band radiated by these lighting devices, so it will not be interfered. MIC s infrared wireless microphone is controlled by PLL, and the frequency is more stable. The projector s projector switch has been verified in the classroom. MIC s infrared microphone can still work normally without any interference.

4 Are infrared microphones subject to interference from plasma TVs?

Plasma TVs radiate very strong infrared light. This is clear to everyone, and the plasma TVs of different brands and different display sizes illuminate the spectrum of infrared light that radiates after lighting, which is technically impossible to avoid. All plasma TVs may radiate infrared light frequencies, so it is difficult for infrared microphones to be truly immune to plasma TV interference. At present, the better method is to not use it with plasma TVs as much as possible, and you can choose LCD, projection, rear projection, ordinary TVs, etc. as display equipment; or shield the infrared rays radiated by plasma TVs to reduce plasma TVs. Of infrared light radiation, the current ideal shielding material is automotive riot film.

5. Is it that the more mirrors used in the private room, the more favorable the infrared microphone reception is?

It turns out that the more mirrors used in the private room, the worse the infrared microphone's reception. Although the energy loss of the mirror surface in the process of light reflection is very small, the mirror surface will reflect the optical signal in one direction, which objectively hinders the formation of a dense optical network in a relatively sealed space, resulting in the formation of blind spots in the space. For large-area mirror interiors, it can be overcome by increasing the number of receiving heads to achieve a satisfactory receiving effect.

6. Are there any restrictions on the use of infrared wireless microphones in entertainment venues?

There is no limit in quantity. The infrared wireless microphone has only two frequency points to distinguish the two microphones used in the same space, that is, the two channels A and B. Since infrared light cannot penetrate the wall or opaque partitions, the same The systems will not interfere with each other. Can be used indefinitely. This feature of the infrared microphone makes it very suitable for working in KTV boxes and classrooms, without the need for troublesome frequency modulation, and without the embarrassment of wrong microphones.

7. The infrared microphone is used in two adjacent spaces. When the door is opened, will it interfere with each other?

Normally, there is no interference, but there is a possibility of interference in theory. Although the infrared light may enter the adjacent space through the opened door, the light entering through the door is weaker in energy than the infrared microphone in the space, at least an order of magnitude difference. The receiving host always responds to the same frequency signal. It accepts high-energy (high-intensity) signals, so there is almost no possibility of receiving infrared rays entering through the door. At the same time, adjusting the position of the receiving head can also reduce the possibility of interference between the gate and the gate signals.

8. Can using infrared microphones reduce the number of spare microphones?

This is indeed the case. Due to the unparalleled versatility of infrared wireless microphones, any set of microphones can be used in any relatively independent space without having to consider the problem of frequency interference. At the same time, all hair transmitters are also universal. Any A pair of A and B channel transmitters can work with any receiving host system without having to consider the frequency correspondence between transmitting and receiving, so the number of spare microphones can be greatly reduced, and the room opening rate due to microphone failure can be reduced. A low situation happens.