Wireless Microphone

Wireless Microphone systems are designed to replace the cable that usually tethers a wired microphone (or any acoustic transducer) to an amplifier. A Wireless Microphone system begins with a typical microphone which responds to sound waves, and delivers essentially equivalent audio frequency electrical waves to an input of a transmitter. The transmitter "sends" a signal to an associated receiver which is connected to the input of the sound reinforcement amplifier, or mixer. The receiver "picks-up" the transmitter signal, and then converts this signal to a usable audio signal which is sent to the sound reinforcement amp or mixer.

Components of Wireless Microphone Systems:

Microphone or Transducer: Any Wireless Microphone or transducer can be converted to wireless operation with the addition of a transmitter and receiver wireless link. Wireless Microphone as well as piezoelectric pickups commonly used in guitars are the heart of the system long before a transmitter and receiver come into play. It is often said that "garbage in is garbage out," and this phrase couldn't be more true with a wireless system. Any system is only as good as its weakest link, and generally the least expensive way to improve the overall quality of the Wireless Microphone system is to improve the microphone or transducer. A suitable Wireless Microphone should have excellent dynamic range and headroom, and good linearity over the audio range or the end result will be disappointing. When a Wireless Microphone system is used, it should include a high quality microphone that is matched to the application.

Transmitters: The transmitter provides the link between the Wireless Microphone and the receiver. The transmitter takes the audio signal from the Wireless Microphone, converts this energy into a frequency modulated carrier (FM) then radiates the modulated RF carrier where it is picked-up by the receiver.

Receivers: The Wireless Microphone receiver reverses the process by receiving the RF signal and converting the carrier signal into a usable audio signal. This is accomplished by a process called heterodyning where the carrier is filtered, then converted to an intermediate frequency (IF) which is a fraction of the original carrier frequency. After filtering in the IF section, the signal is sent to an FM demodulator which separates the superimposed audio signal from the RF carrier, and converts it into a usable microphone signal again. The usable audio signal is then fed to the output which is connected to the amplifier or mixer. The receiver acts like a standard microphone when used in conjunction with a transmitter and Wireless Microphone.

There are numerous variations of both transmitters and receivers depending on the particular application in Wireless Microphone. There are ways in which we can explore both receivers and transmitters in depth, but we need to begin by examining the different frequency groups applicable to Wireless Microphone first.