3D printed wideband harmonic transceiver for embedded passive wireless monitoring

A three-dimensional (3D) wideband passive harmonic transceiver for long-range embedded wireless monitoring is presented. The wideband performance is achieved by integrating two harmonic repeaters with adjacent centre frequencies. Each repeater consists of a frequency doubler and conjugate-matched receive and transmit meandered monopole antennas. The transceiver operates by receiving a signal at f(1) between 2.35 and 2.85 GHz and re-radiating a signal at 2*f(1) and is optimised for low-power operation. The node fits within a lambda/8.3 (at 2.4 GHz) diameter sphere and weighs 2.5 g. The transceiver maximum expected efficiency is 5.6% at -18 dBm input power. The transceiver is fabricated via direct print additive manufacturing.