Three-wire SPI Design: This ADF4351 source development board adopts with three-wire serial peripheral interface design to provide an easy operation. The three-wire SPI leads to control pin and state locking pin, which can achieve all the features, including point frequency sweep and frequency hopping, and according to the crystal frequency, the step frequency can be 0.1K to 1K Easy to Operate: This Source Development Board is easy and convenient to operate. It can be controlled by the upper computer official software, so you can control it easily, and all control pins are leaded out by three-wire SPI for convenient operation, you can control it through three-wire SPI easily Excellent Design: This RF Source Development Board has well designed circuit board layout, which could provide a long-lasting good performance for you Crystal Oscillator Design: There's a default + -50ppm 25M active crystal oscillator, with which the circuit diagram in PDF format and STM32 test program are provided Isolation Applications: This Source Frequency Synthesizer Development Board has isolation applications, the RF output level can mute, and the mute function can be controlled either by pin or software, and it also provides auxiliary RF output that can be turned off when not in use