Self-Aligned and Low-Capacitance Lateral GaN Diode for X-Band High-Efficiency Rectifier

In this letter, we proposed to implement a self-aligned and low capacitance GaN microwave diode in an X-band rectifier circuit for high-efficiency and high-power microwave power transmission application. Benefited from the advanced structural design, GaN microwave diode demonstrates a low on-resistance of
$1.61 {\Omega } \cdot $
mm, low junction capacitance (
$\text{C}_{\text {j}}$
) of 0.223 pF/mm at 0 V bias, and high breakdown voltage (BV) of 75 V, achieving a high cut-off frequency (
$\text{f}_{\text {T}}$
) of 443 GHz and
$\text{f}_{\text {T}} \times $
BV figure-of-merit (FOM) of 33.2 THz
$\cdot \text{V}$
. By incorporating the advanced GaN diode in the X-band rectifier circuit, the rectifier demonstrates a high conversion efficiency of 80.1% at an input power of 25.2 dBm, frequency of 10 GHz and load resistance of
$650 {\Omega }$
, which is the highest X-band rectifier efficiency ever reported, showing its great potential for future high-efficiency and high-power microwave power transmission.