关于ADL5354RF混频的设计

　　ADL5354是高度线性双平衡（RF和LO平衡）RF混频器，输入频率从2300 MHz 到2900 MHz.ADL5354混频器工作在2300至2900MHz 频率范围，提供极高的集成度，内置射频巴伦、用于双通道本振频率应用的本振开关、本振驱动器和集成式中频放大器。巴伦的集成使射频信号可被单端驱动，集成式中频放大器可以提供必要的增益，因而无需外部增益级电路。ADL5354可提供的IP3和噪声指数性能，因而可以实现优异的无杂散动态范围。这些混频器还能提供强干扰信号下出色的噪声指数性能。高的无杂散动态范围和阻塞器性能下的低噪声指数使得这些混频器可用于接收机在有大干扰信号情况下工作的场合。5V（标称值）的 ADL5354也能在功耗敏感应用中的3.3V 电源电压下工作。

　　双通道ADL5354混频器工作在2300至2900MHz频率范围，提供极高的集成度，内置射频巴伦、用于双通道本振频率应用的本振开关、本振驱动器和集成式中频放大器。巴伦的集成使射频信号可被单端驱动，集成式中频放大器可以提供必要的增益，因而无需外部增益级电路。

　　The ADL5354 uses a highly linear, doubly balanced, passive mixer core along with integrated RF and local oscillator （LO） balancing circuitry to allow single-ended operation. The ADL5354 incorporates the RF baluns, allowing for optimal performance over a 2300 MHz to 2900 MHz RF input frequency range. The balanced passive mixer arrangement provides good LO-to-RF leakage, typically better than ?35 dBm, and excellent intermodulation performance. The balanced mixer core also provides extremely high input linearity, allowing the device to be used in demanding cellular applications where in-band blocking signals may otherwise result in the degradation of dynamic performance. A high linearity IF buffer amplifier follows the passive mixer core to yield a typical power conversion gain of 8.2 dB and can be used with a wide range of output impedances.

　　The ADL5354 provides two switched LO paths that can be used in TDD applications where it is desirable to ping-pong between two local oscillators. LO current can be externally set using a resistor to minimize dc current commensurate with the desired level of performance. For low voltage applications, the ADL5354 is capable of operation at voltages down to 3.3 V with substantially reduced current. Under low voltage operation, an additional logic pin is provided to power down （<300 μA） the circuit when desired.

　　The ADL5354 is fabricated using a BiCMOS high performance IC process. The device is available in a 6 mm × 6 mm, 36-lead LFCSP and operates over a ?40℃ to +85℃ temperature range.

　　ADL5354主要特性：

　　RF frequency range of 2300 MHz to 2900 MHz

　　IF frequency range of 30 MHz to 450 MHz

　　Power conversion gain: 8 dB

　　SSB noise figure of 10 dB

　　Input IP3 of 25 dBm

　　Input P1dB of 11 dBm

　　Typical LO drive of 0 dBm

　　Single-ended, 50 Ω RF and LO input ports

　　High isolation SPDT LO input switch

　　Single-supply operation: 3.3 V to 5 V

　　Exposed paddle, 6 mm × 6 mm, 36-lead LFCSP

　　ADL5354应用：

　　Cellular base station receivers

　　Transmit observation receivers

　　Radio link downconverters

　　图1.ADL5354功能方框图

　　图2.ADL5354典型应用电路图

　　图3.ADL5354评估板电路图

　　ADL5354评估板元件配置表

　　图4.ADL5354评估板顶层布局图

　　ADL5354可提供的IP3和噪声指数性能，因而可以实现优异的无杂散动态范围。这些混频器还能提供强干扰信号下出色的噪声指数性能。高的无杂散动态范围和阻塞器性能下的低噪声指数使得这些混频器可用于接收机在有大干扰信号情况下工作的场合。5V（标称值）的ADL5354也能在功耗敏感应用中的3.3V电源电压下工作。