Antenna-Electronics Co-Design — Multi-Feed Antennas Based mm-Wave Front-Ends for On-Antenna Power Combining, Active Load Modulation, and Polarization-Division-Duplex Communication

Traditionally, antennas and electronics are often treated as two distinct and separated domains: antenna designers handle the antennas; circuit designers deal with the electronics; and they only talk to each other over one single standard 50-Ohm interface. It is noteworthy that the far-field antenna radiation characteristics are completely governed by its local current and voltage distributions, suggesting the possibility of using “multiple distributed electronic feeds” to “actively synthesize” the desired antenna responses. In addition, since on-chip antennas have become ubiquitous at mm-wave and cost of adding more on-chip circuits are negligible, boundaries of these two domains are further blurred, and thus, multi-feed antennas co-integrated with complex electronics now emerge as a very promising technology choice particularly for mm-wave communication systems. In this talk, we will present several recently reported multi-feed radiators co-integrated with complex transmitter/receiver electronics to achieve unprecedented mm-wave front-end performance. On-chip or on-package multi-feed antennas can support low-loss on-antenna power combining in one single antenna footprint, radically pushing the limit of output power and efficiency for mm-wave transmitters. The multi-feed antennas also enable on-antenna active load modulation, achieving high-efficiency on-antenna Doherty or Outphasing transmitters in silicon with state-of-the-art energy efficiency. Furthermore, inherently wideband feed isolation is explored in multi-feed antennas to realize mm-wave polarization-division-duplex wireless links with multi-Gbit/s modulated signals.