Micro-wave linear analog phase modulator at X frequency range

Abstract

The invention provides a micro-wave linear analog phase modulator at an X frequency range, which is characterized in that output ends of two paths of a Lange bridge are respectively connected with a VCD (variable capacitance diode) by reflection matching circuits; microwave signals are divided into two paths of orthogonal signals with equal amplitude and 90-degree phase difference by the Lange bridge; the orthogonal signals are echoed by the VCD to form two paths of echoed signals with the same amplitude and phase by the reflection matching circuits; the two paths of echoed signals are returned to the Lange bridge by the reflection matching circuits, and are subjected to inverting offset at an input end of the Lange bridge in the mode of the same amplitude and opposite phases, thus the echoed signals do not exist at the input end; the echoed signals are subjected to in-phase superposition at an output end of the Lange bridge in the mode of the same amplitude and phase, thus the microwave signals can be transmitted in one direction from the input end of the Lange bridge to the output end of the Lange bridge; the junction capacitance of the VCD is changed with the change of a control voltage, thus the phases of the echoed signals are changed with the change of the control voltage, thereby realizing microwave linear phase modulation; and the echoed matching circuits can increase the phase variable quantity of the echoed signals of the VCD so as to increase the modulation depth.

Description

technical field [0001] The invention discloses a microwave linear analog phase modulator, which is especially suitable for the technical field of measurement and control of deep-space aircraft. Background technique [0002] The deep space measurement and control transponder uses the X-band downlink, and the ranging tone and the telemetry sub-carrier signal perform linear phase modulation on the carrier. [0003] The downlink of domestic spaceborne TT&C transponders uses S-band and C-band, and the modulation method is linear phase modulation. The realization method is to carry out linear phase modulation at the intermediate frequency first, and use a microwave frequency multiplier to multiply to the S frequency band and the C frequency band. In order to ensure the spectral purity, it is necessary to add a band-pass filter at the output end of the frequency multiplier, which is relatively large in size. Due to the poor temperature stability of the frequency multiplier, the p...

AI Technical Summary

Problems solved by technology

Due to the poor temperature stability of the ferrite ring, the phase shift of the phase modulator with temperature changes to nearly 40° (-20°C ~ 74°C)

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