First Demonstration of L-Band High-Power Limiter with GaN Schottky Barrier Diodes (SBDs) Based on Steep-Mesa Technology

Abstract

Gallium nitride (GaN) has attracted increased attention because of superior material properties, such as high electron saturation velocity and high electrical field strength, which are promising for high-power microwave applications. We report on a high-performance vertical GaN-based Schottky barrier diode (SBD) and its demonstration in a microwave power limiter for the first time. The fabricated SBD achieved a very low differential specific on-resistance (RON,sp) of 0.21 mΩ·cm2, attributed to the steep-mesa technology, which assists in reducing the spacing between the edge of the anode and cathode to 2 μm. Meanwhile, a low leakage current of ~10−9 A/cm2@−10 V, a high forward current density of 9.4 kA/cm2 at 3 V in DC, and an ideality factor of 1.04 were achieved. Scattering parameter measurements showed that the insertion loss (S21) was lower than −3 dB until 3 GHz. In addition, a microwave power limiter circuit with two anti-parallel diodes was built and measured on an alumina substrate. The input power level reached 40 dBm (10 watts) in continuous-wave mode at 2 GHz, with a corresponding leakage power of 27.2 dBm (0.5 watts) at the output port of the limiter, exhibiting the great potential of GaN SBD in microwave power limiters.

Power Compression and Phase Analysis of GaN HEMT for Microwave Receiver Protection

“…The improvement of the power compression of this GaN HEMT RP was at the expense of DC power consumption. The GaN HEMT RP in this work presented a better power limiting capability than diode-based RPs reported in the literature [7,31,32]. As shown in Figure 3c, when the injection power was 17 dB higher than individual threshold power levels, the GaN HEMT RP had 2~4 dB more power compression than those diode-base RPs.…”

“…A low insertion loss of 0.3 dB has also been reported for a diamond diode based RP at an operation frequency of 1 GHz [9]. However, for a diode-based RP, typically a tradeoff often has to be made between C off and R on [7][8][9]. Although diode-based RPs have made steady progress, they still face some important challenges, such as insufficient power compression, inadequacy in tuning their threshold power level (the input power with 1-dB gain compression), and sensitivity to frequency change.…”

“…An RP allows input power below a certain value to pass through ideally without loss, and attenuating input signal strength when it exceeds the threshold. A number of device technologies have been developed to achieve RF and microwave RPs, including Schottky barrier diodes (SBDs) [5][6][7], p-i-n diodes [3,8,9], and transistors [10][11][12]. Employing a steep-mesa technology, a gallium nitride (GaN) SBD based RP demonstrated a low on-resistance (R ON ) and a power compression of 3.3 dB with a corresponding input power of 20 dBm at 2 GHz [7].…”

“…A number of device technologies have been developed to achieve RF and microwave RPs, including Schottky barrier diodes (SBDs) [5][6][7], p-i-n diodes [3,8,9], and transistors [10][11][12]. Employing a steep-mesa technology, a gallium nitride (GaN) SBD based RP demonstrated a low on-resistance (R ON ) and a power compression of 3.3 dB with a corresponding input power of 20 dBm at 2 GHz [7]. A low insertion loss of 0.3 dB has also been reported for a diamond diode based RP at an operation frequency of 1 GHz [9].…”

Design of microwave β-(Al x Ga 1− x )2O3/Ga2O3 lateral Schottky barrier diodes

“…In this case, the higher order terms of power series of diode current become dominant and DC component become nearly constant [47,52]. This, in turn, create the self-heating of SBD and lead to physical failure which were observed in [53]. The saturation was observed at P in,th ∼ 38 dBm for proposed β-(Al x Ga 1−x ) 2 O 3 /Ga 2 O 3 LSBD.…”