A Power Amplifier (PA) module operating in the D-band has been developed. The design includes a Radio Frequency (RF) input/output transition structure and a Direct Current (DC) voltage regulation timing circuit. The RF input/output transition structure utilizes a waveguide-coplanar waveguide transition based on wedge-shaped waveguide film, achieving co-directional conversion and reducing the impact of the gap between the power amplifier chip and the cavity on module performance through a gold wire bonding method similar to coplanar waveguides. The drain bias circuit enhances the stability of the DC voltage regulation timing circuit by paralleling two voltage regulation chips. The design of the choke slot structure effectively reduces the transmission loss when modules are cascaded. Test results indicate that the module has a small-signal gain greater than 10 dB and a maximum gain greater than 17 dB within the 144~166 GHz range; the output power is greater than 27 dBm, with a maximum output power greater than 31 dBm.