Analog Devices Inc. HMC137

Overview

HMC137 from Analog Devices (formerly Hittite Microwave) is a GaAs MMIC bi-phase modulator die operating in the 6–11 GHz RF band, providing 20 dB typical carrier suppression, 11 dB typical insertion loss, and ±0.5 dB amplitude balance for microwave point-to-point radio transceivers.

For engineers reviewing the HMC137 datasheet, HMC137 pinout, HMC137 application, or HMC137 equivalent, this page delivers verified electrical specs, die-level mounting guidance, functional role as phase modulator/demodulator/phase comparator, and validated alternative options for RF front-end design.

Technical Context

The HMC137 implements a monolithic balanced diode architecture with integrated baluns to enable direct RF phase modulation between 0° and 180° states via polarity-controlled DC bias at the IF port. It operates with 5 mA nominal bias current and requires no external matching networks at RF and LO ports due to internal 50 Ω DC-coupled termination.

As a demodulator, it outputs baseband data at the IF port when a modulated RF signal is compared against a clean LO reference; as a phase comparator, it generates an analog voltage proportional to the phase difference between RF and LO inputs - both functions rely on the same core Schottky diode pair topology.

Key Specifications

Pinout & Package

Package: Bare die (GaAs MMIC), dimensions 1.45 × 1.30 × 0.1 mm, gold metallized bond pads, backside grounded, supplied in WP-3 waffle pack.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bi-phase modulator applications.

Compared with HMC137, HMC529LP4E offers higher-frequency capability but sacrifices carrier suppression and die-level integration, while ADL5375-05 shifts architecture toward full IQ modulation at lower frequencies - neither is pin-compatible, and both require layout and driver circuit changes.

Availability

HMC137 is available at Aetrix Electronics and suitable for wireless local loop infrastructure, LMDS terminal units, and point-to-point radio transceivers requiring stable component supply of obsolete yet field-proven GaAs MMIC modulators.

Supply support for HMC137 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices acquired Hittite Microwave in 2014 and maintains legacy MMIC product support, including obsolescence management and controlled-batch sourcing for high-reliability RF applications.

The HMC137 belongs to Hittite's legacy GaAs MMIC modulator family, designed specifically for microwave communication systems requiring compact, high-performance phase modulation in fixed wireless and test instrumentation.

FAQ

What is the primary function of the HMC137?

The HMC137 is a GaAs MMIC bi-phase modulator that phase-modulates an RF signal into 0° or 180° states based on polarity of DC bias applied to its IF port. It also functions as a demodulator or phase comparator. The HMC137 achieves this using monolithically integrated baluns and Schottky diodes, delivering 20 dB typical carrier suppression in the 6–11 GHz band - a key performance metric for the HMC137 in microwave transceiver designs.

Is the HMC137 still in production?

No - the HMC137 is marked OBSOLETE by Analog Devices, but Aetrix Electronics maintains traceable inventory of original-wafer lots with full lot traceability and handling documentation. The HMC137 remains available for legacy system repair, military/aerospace sustainment, and industrial deployments where redesign is cost-prohibitive.

What bias conditions are required for optimal HMC137 performance?

The HMC137 requires a nominal 5 mA DC bias current at the IF port to achieve specified carrier suppression and linearity. The datasheet specifies a 2–10 mA operating range, with forward biasing of internal Schottky diodes producing ~0.6 V at the IF port. Exceeding 2 mA sourcing/sinking capability risks non-function or die failure - a critical constraint for the HMC137's safe operation.

Can the HMC137 be used as a phase detector?

Yes - the HMC137 functions as a phase comparator: when two RF signals are applied to the RF and LO ports, the resulting analog voltage at the IF port is proportional to their phase difference. This behavior is explicitly documented in the HMC137 datasheet and leveraged in RF test equipment calibration. The HMC137's phase comparator mode does not require external components beyond proper DC biasing.

What packaging options exist for the HMC137?

The HMC137 is supplied exclusively as a bare die in WP-3 waffle pack format, measuring 1.45 × 1.30 × 0.1 mm with gold bond pads and grounded backside metallization. No leaded or laminate-packaged variants exist. Mounting requires eutectic (AuSn) or conductive epoxy die attach to a grounded RF substrate - a defining mechanical requirement for the HMC137's integration.