MICROGOLFANTENNE.

摘要

1282320 Aerials HOLLANDSE SIGNAALAPPARATEN NV 13 Oct 1969 [13 Oct 1968] 50222/69 Heading H4A An aerial system comprises a plurality of linear arrays of radiators and a transmission line network coupled thereto. The network has a plurality of transmission lines for signals in respective different frequency bands, and a respective frequency-selective coupling arrangement coupling each array to each line only at the frequency band associated with that line. As described, an aerial 1 comprises four linear slotted waveguides 3, 4, 5, 6 which are disposed in parallel with their slotted faces co-planar. One end of each waveguide is terminated in a non-reflecting load 14 and the other end is connected to a first port of a respective diplexer 9, 10, 11, 12. A supply line 7 operating in a frequency band I is connected to a second port of each diplexer through respective directional couplers 22, 23, 24, 25 and a supply line 8 operating in a frequency band II is connected to a third port of each diplexer through respective directional couplers 221, 231, 241, 251. The far ends of the lines 7, 8 and the fourth ports of the diplexers are terminated in non-reflecting loads (15, 16 and 21, respectively). Each diplexer 9, 10, 11, 12 comprises two filters 20, 201, passing only the frequency band II, on each side of which are directional couplers 19, 191 in the form of short-slot hybrids. When transmitting, the diplexers combine power of each frequency band into each linear array and, when receiving, the diplexers separate power of each frequency band into the appropriate supply line. The shape of the radiated beam for each frequency band may be controlled by adjusting the lengths of the appropriate supply line between consecutive directional couplers, and the coupling factors of said couplers. For example, a cosecsquared shaped beam may be used for signals of frequency band I and a pencil shaped beam for signals of frequency band II. The said pencil shaped beam may be scanned by varying the frequency of the signals to the supply line 8, and the dispersion of said line may be increased by making it of serpentine form. Dispersion in the supply line 7 may be compensated by means of phase-shifters 26.