To use a smaller antenna, we need a higher signal frequency, and that’s what we do when we apply modulation to the signal. Modulation is simply encoding the low frequency signal in the information of ...

The diagram utilizes two BC548 transistors, more importantly descent results although not as good as RF transistors which provide high performance at wide bandwidth. It also utilizes electret ...

Mechanical antennas represent a disruptive approach to low-frequency communication by exploiting the mechanical oscillation of electric charges or magnetic dipoles to generate electromagnetic ...

The Family Radio Service, or FRS, is a system allowing short-range communications between friends and/or family. The system uses frequency modulation, or FM, signals, improving on the older citizen's ...

Note: we are working to recover the figures for this article. The process of designing a short-range radio system can be complex and often involves many project tradeoffs (Fig. 1). With a little ...

To send or receive a radio signal requires an ability to select a particular frequency from the limitless spectrum available. Electronically, the trick boils down to finding circuits that respond, or ...

A new simpler, cheaper and potentially more effective way to prevent radio antennas from picking up unwanted signals has been created by researchers in the US. With further development, the technique ...

Modulation is the process of varying a higher frequency carrier wave to transmit information. Though it is theoretically possible to transmit baseband signals (or information) without modulating it, ...