GB1524495A - Delay line phase shifters - Google Patents

Abstract

1524495 Phase modulators MARCONI CO Ltd 31 March 1977 [8 April 1976] 13588/77 Heading H3R In an SAW delay line phase shifter suitable for use in a phased array or commutated array antenna system and providing a single of a plurality of constant amplitude outputs with variable and large phase swings (”2# radians), a frequency dependent phase shift is imposed on a variable frequency f 1 or a side-band frequency e.g.f 0 -f 1 ) by passing it through a SAW delay line and this phase shift is transposed on a signal of frequency f 0 by employing modulators M 1 , M 2 to effect appropriate combination and filters BP 1 , BP 2 to filter out unwanted sidebands. The phase of the output signal of frequency f 0 is varied by a variation of the frequency f 1 of oscillator VCO. Effects of the temperature on the circuit operation may be minimized by forming (Fig. 4, not shown) part of the oscillator feed-back phase shift path and the delay line on the same substrate. A plurality of outputs at different phase may be obtained by using different tappings on the delay line. For multi-phased input reception, the multiple inputs (Fig. 3, not shown) are shifted to a side-band frequency by f 1 and the side-bands undergo varying phase shifts before combination and reconversion to the original frequency f 0 .