Low-power CMOS transceivers with on-chip antennas for short-range radio-frequency communication

The benefit of an on-chip antenna is the possibility for smaller size and fewer external components. If an on-chip antenna is combined with power scavenging circuits to eliminate the external battery, it is possible to achieve true fully integrated transceivers. However, there are many challenges to overcome and compromises to be made. The use of an on-chip antenna will typically result in lower communication range, and the impedance of such antenna may not be as convenient for interfacing. Similarly, the choice of operating frequency involves a tradeoff between antenna efficiency and power consumption in the active circuitry. In order to operate with minimum power to allow for the possibility of using scavenged power, it is possible for circuitry to be shut down when it is inactive; however, this requires more careful consideration of synchronization circuits. These are some of the issues that will be discussed in the context of several examples including an RF transceiver designed for 5.2 GHz operation and intended for short range communication with biomedical sensors.