Unitary antenna-receiver utilizing microstrip conductors
United States Patent 2874276

809,482. Strip transmission line networks. STANDARD TELEPHONES & CABLES Ltd. May 11, 1956 [May 13, 1955], No. 14706/56. Class 40 (8). A strip transmission line for microwave frequencies comprises a ground-plane conductor 30 of approximately C-shaped cross-section and a round or ribbon-like line conductor 34 positioned between the in-turned ends of the ground-plane conductor. The line may be applied to the construction of filters, in which case two critically-spaced gaps 18, 19 in the conductor 34 are arranged to enclose a resonant section 35. The resonant portion of the line is supported either by a central dielectric block 39 or by posts 26 positioned at the extremities of the section 35 adjacent the gaps. The posts act as coupling loops and may also be placed at the ends of the sections 36, 37 on either side of the resonant section. The filter may be joined at either end to dielectric-filled strip transmission lines 41, 42 of known type, the necessary impedance transformation being provided by tapered portions 27 of dielectric beneath the conductor sections 36, 37. Since (in the construction shown) the dielectric in the filter section consists of air, the spacing between line and ground conductors is diminished and this may be achieved by the provision of conductive inserts 40 in the ground-plane conductor 30. Alternatively, the line conductor sections may be bent into closer proximity to the conductor 30. It is stated in the Specification that the main field of the propagated energy occurs in the gap d and that the width of this gap, for minimum loss, should be about 1/5 of the distance between the line conductor and the portion of the ground-plane conductor immediately beneath it. Propagation of spurious modes may be prevented by shortcircuiting posts 38. The centre frequency of the filter may be adjusted by controlling the slight amount of energy radiated by the gap d. To this end, the top of the filter section is enclosed in a metallic cover 43 carrying an adjustable screw 44. Specifications 709,351, [Group XL (c)], 761,761, 761,763 and 761,778 are referred to.

Cuthbert, Dukes John Marcus
John, Kemp
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Other Classes:
333/116, 333/120, 343/818, 343/846, 455/281, 455/327, 455/328
International Classes:
B07C3/00; H01P1/18; H01P1/203; H01P1/209; H01P3/08; H01P5/02; H01P5/08; H01P5/107; H01P5/12; H01P5/18; H01P5/22; H01Q1/24; H01Q9/06; H03L7/04
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