Abstract: In this paper, design and experiment results for a hybrid integrated detector whose center frequency is 35 GHz with 5 GHz bandwidth are presented. The input port of the detector is the form of standard rectangular waveguide. The waveguide to microstrip transition is realized by probe transition. By using high frequency electromagnetic simulation and microwave circuit CAD software, the design of the detector is accomplished. Simulations show that the detector has excellent performance, which is agreed with the test results.