**HMC589AST89E: A Comprehensive Technical Overview and Application Guide**

The **HMC589AST89E** represents a significant advancement in the field of **integrated microwave technology**, specifically as a highly versatile **GaAs MMIC Double-Balanced Mixer**. Designed to operate from **RF frequencies of 9 to 12 GHz** with an exceptionally **wide IF bandwidth from DC to 9 GHz**, this component is engineered for superior performance in demanding applications. Its core functionality is to translate high-frequency signals down to a lower, more manageable frequency range for processing, or vice versa for up-conversion, making it a cornerstone in modern RF systems.

A key performance metric for any mixer is its **conversion loss**, and the HMC589AST89E excels with a typical value of **8.5 dB**. This low loss is critical for maintaining the signal-to-noise ratio (SNR) of the entire system. Furthermore, it boasts outstanding **port-to-port isolation**, particularly from the Local Oscillator (LO) port to both the Radio Frequency (RF) and Intermediate Frequency (IF) ports. This high isolation, typically exceeding **30 dB**, is paramount as it prevents the powerful LO signal from leaking into other parts of the circuit, which can cause self-interference, de-sensitization, and other spurious effects. The mixer also requires a relatively low **LO drive power of +13 dBm**, simplifying the design of the preceding LO amplifier stage.

The operational principle hinges on the LO signal switching the internal Schottky diodes. When a sufficiently strong LO signal is applied, it acts as a pump, rapidly turning the diode quad on and off. This switching action effectively multiplies the RF input signal, creating the sum (RF + LO) and difference (RF - LO) frequencies at the output. A low-pass filter is then typically used at the IF port to select the desired difference frequency, completing the down-conversion process.

**Application Guide and Circuit Considerations**

The HMC589AST89E is ideally suited for a broad spectrum of high-frequency systems. Its primary applications include:

* **Point-to-Point and Point-to-Multi-Point Radios:** Essential for up-converting and down-converting signals in the licensed and unlicensed microwave bands used for wireless backhaul.

* **Military and Aerospace Systems:** Its robust performance makes it suitable for **electronic warfare (EW)**, radar, and satellite communication systems where reliability and wide bandwidth are non-negotiable.

* **Test and Measurement Equipment:** Used as a fundamental building block in high-performance signal analyzers, signal generators, and frequency synthesizers.

* **Fiber Optic and VSAT Systems:** Facilitates the necessary frequency translation in high-speed data links.

For optimal performance, careful circuit design is mandatory. The component requires external **DC blocking capacitors** on all three ports (RF, LO, IF) and **RF chokes** to provide a DC return path for the internal diodes. The printed circuit board (PCB) material must be chosen for its low loss and stable dielectric constant at microwave frequencies, such as Rogers RO4003C or similar. Proper grounding via numerous plated through-holes around the package is critical to minimize parasitic inductance. All signal lines must be impedance-controlled to 50 Ohms to prevent standing waves and signal reflections that degrade performance.

**ICGOODFIND**

**ICGOODFIND**: The HMC589AST89E stands out as a premier solution for high-dynamic-range frequency conversion in the X-band and Ku-band spectra. Its combination of **wide IF bandwidth**, **low conversion loss**, and **excellent LO-to-RF/IF isolation** makes it an indispensable component for designers pushing the limits of modern microwave communication, radar, and test systems. Careful attention to biasing, PCB layout, and component matching is essential to fully leverage its advanced capabilities.

**Keywords:**

**Mixer**

**MMIC**

**Isolation**

**Conversion Loss**

**Bandwidth**