Abstract
Dynamic load modulation (DLM) is a technique for increasing radio frequency (RF) power amplifier (PA) efficiency when amplifying amplitude modulated signals. It does this by manipulating a tuneable matching network (TMN) between the PA and the antenna in harmony with the envelope of the transmitted signal. The TMN is usually based on varactor diodes, requiring control voltages with up to 100 V peak-to-peak swing. Conventional off-the-shelf op-amps cannot produce a big enough voltage swing at sufficient speed, especially when amplifying modern communications standards like the 3GPP 4G Long Term Evolution (LTE). The discrete current mirror driver amplifier described here capable of producing 50V peak-to-peak voltage swing. When the driver amplifier was combined with a suitable RF PA and TMN, 46.0% DC-to-RF efficiency was achieved at 33.9 dBm output power (POUT) with a 1.4 MHz LTE signal. The adjacent channel power ratio (ACPR) was -40 dBc, confirming that the current mirror amplifier is suitable for LTE use.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
