Planar Monolithics (PMI) Model PLO-48D4G-EXT is an externally referenced Phase Locked Dielectric Resonator Oscillator (PLDRO) covering the frequency of 48.4 GHz with a load VSWR: 1.5:1; output power of 10 dBm minimum; spurious of 60 dBc; phase noise of 102 dBc/Hz @ 100 kHz; harmonics of 20 dBc; and a 100 MHz (Sine Wave) external reference.  Housing size is 2.25” x 2.25” x 0.62” with 2.4mm female (RF OUT) and SMA female (REF IN) connectors.  https://www.pmi-rf.com/product-details/plo-48d4g-ext