The Design and Implementation of High Frequency Signal Generator Based on DDS

DDS direct digital frequency synthesis, is a key digital technology. The system to DDS technology as the core, consists of AD9910, STM32 module, TFTLCD display module, filter circuit, automatic level control module. Compared with the traditional frequency synthesizer with a low cost, low power consumption, high resolution, fast switching time, good Spurious suppression, etc. The system is to develop a high-frequency sinusoidal signal generator, which is based on the integrated DDS chip-AD9910 and used the STM32 MCU as control unit. The signal generator can adjust frequency, phase and amplitude of the signal by touching the keyboard on the TFTLCD screen and the value will be displayed on the screen. In addition it has AM,FM,PM modulation and sweep function. The function of the signal generator to achieve the following innovations: (1) High frequency, full functioning; (2) Cancel the button, with the touch screen of the virtual button instead, Combine the keys with the display; (3) Using Chebyshev filter to achieve multi-level filtering, the output bandwidth of 400MHz; (4) back-end high-frequency amplifier circuit using OPA695 design, the amplifier 2 times the output bandwidth of 800MHz bandwidth, input 400MHz signal output amplitude up to 1Vpp; (5) Compared to other solutions, it greatly shortening the development cycle.