GB1289351A - - Google Patents

Abstract

1289351 Waveguide coupling components STANDARD TELEPHONES & CABLES 30 June 1970 [7 July 1969] 34159/69 Heading H1W A microwave transmission system comprises component interconnected by waveguide operated in the evanescent mode (i.e. dimensioned below cut-off) with capacitative tuning elements. The components in addition are preferably constructed in waveguide operated in the evanescent mode such that the system is suitable for construction as a miniaturized integrated system. At the input of an evanescent section of waveguide the impedance is inductive and in each interconnecting waveguide section there are provided suitable obstacles whose capacitative reactance is the conjugate of the inductive reactance. In the example in Fig. 3 a crystal mixer is introduced into the circuit and the crystal capacity is the main capacitative tuning element and the design variable in the integrated circuit is the length l of guide connecting the local and signal oscillators to the crystal mixer. In a further embodiment (Figs. 4, 5, not shown) evanescent mode components are employed in an integrated receiver section of a microwave link.