FPGA-based radio frequency signal source circuit

Abstract

The invention discloses an FPGA-based radio frequency signal source circuit. The FPGA-based radio frequency signal source circuit comprises a power supply circuit, an FPGA chip, a working program of the FPGA chip, a DDS chip circuit, a constant-temperature crystal oscillation circuit, a low-pass filter circuit, a radio frequency amplifier, a numerical control attenuator circuit, a clock circuit, an off-chip program storage circuit, a JTAG program unloading and debugging circuit, and an UART serial port circuit. The FPGA-based radio frequency signal source circuit has the characteristics that a single chip integrated DDS chip technology is adopted; the DDS chip is subjected to high-speed control by using the FPGA chip; the work clock of the DDS chip can reach 1 GHz, and the output sinusoidal frequency of the DDS chip can reach 400 MHz; the circuit has a radio frequency output signal power software control function; a radio frequency signal generator circuit can be controlled by external equipment through the UART serial port circuit; the accuracy of a radio frequency output signal is improved by adopting the constant-temperature crystal oscillation circuit; the frequency accuracy is 0.23 Hz; a 14-bit DAC is arranged in the DDS chip.

Description

technical field [0001] The invention relates to a wireless communication system, in particular to an FPGA-based radio frequency signal source circuit. Background technique [0002] In the fields of modern radar, communication and electronic countermeasures, signal generators are widely used, and the requirements for signal indicators are getting higher and higher. Among various types of signal frequency synthesis at present, direct digital frequency synthesis (DDS) technology is a frequency synthesis method developed rapidly in recent years. DDS adopts digital storage technology to realize waveform generation through phase accumulation, amplitude look-up table and digital-to-analog conversion. It has ultra-wide relative bandwidth, ultra-high frequency agility speed, ultra-fine frequency resolution, continuous phase, and full digitalization. , It is widely used due to its superior performance such as easy monolithic integration. [0003] At present, the RF signal source cir...

AI Technical Summary

Problems solved by technology

[0003] At present, the RF signal source circuit is mostly implemented by analog, adopting superheterodyne circuit design, and controlling the VCO voltage-controlled oscillator to generate the required signal frequency through the PLL phase-locked loop. This method can only generate a single sinusoidal signal and a simple analog The modulation method is greatly affected by the environment such as temperature. It is difficult to implement circuits such as loop filters to output signals with a wide frequency range.

Images