A wideband technique for outphasing modulation is introduced that efficiently generates outphasing modulation using differential injection locking between oscillators without requiring digital signal processing. Complex modulation with outphasing signals is demonstrated with two edge oscillators generating outphasing signals locked to a central master oscillator. The coupled-oscillator outphasing modulator circuit is implemented in 45 nm SOI CMOS and delivers 9.2 dBm to a 50    $\Omega $    external load at 8 GHz while consuming only 36.5 mW to achieve a 22.7% overall system efficiency. The modulator provides 30 dB of dynamic range and the measurements demonstrate complex waveforms such as 64-quadrature amplitude modulation with 2.1% error vector magnitude at 60 Mb/s.
['Mohammad Sadegh Mehrjoo', 'James F. Buckwalter']
A Differential Oscillator Injection Locking Technique for an 8 GHz Outphasing Modulator With 22.7% Modulation Efficiency