Waveguide Integrated High-Gain Amplifier Module for Millimeter-Wave Applications

Abstract

Abstract-In this paper, a high-gain amplifier module has been presented for millimeter wave applications. In order to suppress oscillation of the high-gain amplification block, a rectangular waveguide (WG) is fully integrated into the metal case, on which a cascaded two-stage amplifier is mounted. Due to the integrated WG, additional microstrip line (MSL)-to-WG transitions are required. Therefore, a low-loss and wide-band WG-to-MSL transition is designed and fabricated on a 5 mil thick RT5880 substrate. Two sets of WG-to-MSL transitions in back-to-back structure are assembled in the metal case for the high-gain amplifier module and are characterized. The measured transition loss and operational return-loss (S 11 ) bandwidth less than −10 dB are less than −0.44 dB/a transition and 15.9 GHz from 34.1 to 50 GHz, respectively. The fabricated high-gain amplifier module shows a high gain over 39.7 dB from 38 to 41 GHz. At 38.7 GHz, its maximum gain of 44.25 dB is achieved.

High-Gain Amplifier Module Integrating a Waveguide into the Module Case for Millimeter Wave Applications

“…For the high gain amplifier module, the gain more than 39.7 dB was measured at 38-41 GHz. At 38.7 GHz, the maximum gain of 44.25 dB is obtained [15].…”

“…In general, a proactive approach to suppressing this feedback effect is to effectively isolate the two adjacent amplification stages. Figure 1 shows the metal case inserting a 15.7 mm long isolation WG between two cavities for high-gain amplifier module applications [15]. This method allows high-gain amplification without oscillation because of good isolation between two enclosed cavities in the metal case.…”