Analog Devices Inc. HMC136

Overview

HMC136 from Analog Devices (formerly Hittite Microwave) is a GaAs MMIC bi-phase modulator designed for RF phase modulation in the 4–8 GHz band, delivering 30 dB carrier suppression, 10 dB typical insertion loss, and ±6° phase balance. It functions as both a modulator and phase comparator, with DC-coupled RF/LO ports and a current-controlled IF port enabling direct square-wave or analog phase-state switching in microwave transceivers and test systems.

For engineers reviewing the HMC136 datasheet, HMC136 pinout, HMC136 application, or HMC136 equivalent, this page provides verified technical context, validated package and terminal mapping, confirmed RF performance metrics across frequency, and real-world use cases in LMDS, point-to-point radios, and phase-sensitive instrumentation where monolithic die integration and bias-controlled polarity switching are critical.

Technical Context

The HMC136 implements a monolithic balanced diode architecture with integrated baluns to achieve amplitude and phase symmetry between reference and 180° output states. Its IF port accepts 2–10 mA DC bias current to forward-bias internal Schottky diodes, defining output phase polarity without external switching circuitry.

It operates as a passive, current-controlled RF signal router: RF input at Port 2, LO output at Port 3, and IF control at Port 1. Carrier suppression of 30 dBc is achieved under 1 MHz square-wave drive (1.4 V_p-p), while linearity is characterized by +15 dBm input IP3 and +8 dBm P1dB at 6 GHz with 5 mA bias.

Key Specifications

Pinout & Package

Package: Bare GaAs MMIC die in Waffle Pack (WP-2); no leadframe or molded body. Backside metallized gold ground plane requires eutectic or conductive epoxy die attach to RF ground.

Key Features

Applications

Equivalent & Alternatives

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

Compared with HMC571 and QM11014, the HMC136 offers the best trade-off of carrier suppression, phase balance, and low-bias operation specifically within the 4–8 GHz band, making it uniquely suited for precision microwave instrumentation and fixed-wireless infrastructure where die-level flexibility and dual modulator/demodulator capability are essential.

Availability

HMC136 is available at Aetrix Electronics and suitable for wireless local loop transceivers, LMDS base stations, and RF test equipment requiring stable component supply of obsolete but field-proven GaAs MMIC modulators.

Supply support for HMC136 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 its high-frequency RF portfolio, including GaAs and GaN MMICs for defense, communications, and test instrumentation.

The HMC136 belongs to Hittite's legacy MMIC modulator product line, engineered for microwave system integrators needing compact, high-performance die-level phase modulation without hybrid assembly complexity.

FAQ

What is the recommended bias current for optimal carrier suppression in the HMC136?

The HMC136 achieves its specified 30 dBc carrier suppression at 5 mA nominal IF bias current. Operating below 2 mA reduces suppression; exceeding 10 mA risks permanent die damage due to excessive Schottky junction heating. For production tuning, sweep bias from 3–7 mA while monitoring suppression at the target carrier frequency (e.g., 6 GHz) using a spectrum analyzer.

Can the HMC136 be used as a phase detector, and how is its output interpreted?

Yes, the HMC136 functions as a phase detector: apply two signals to RF and LO ports, and measure analog voltage at the IF port. The voltage is linearly proportional to phase difference over ±30°, centered near 0 V at quadrature. This mode is validated in Hittite's application notes for PLL lock detection and phase alignment verification in microwave subsystems using the HMC136.

What mounting method is required for the HMC136 die, and why is backside grounding critical?

The HMC136 must be eutectically attached (AuSn preform, 255°C work surface) or bonded with conductive epoxy directly to a grounded RF substrate. Its gold backside metallization serves as the primary RF ground return path; floating or poorly bonded backside causes severe return loss degradation (>10 dB worse) and instability above 5 GHz due to parasitic cavity resonance.

Does the HMC136 require external DC blocking capacitors, and which ports need them?

Only the IF port may require external DC blocking if the driving source cannot tolerate DC current flow - though the HMC136's IF port is explicitly DC-coupled and designed for direct current injection. RF and LO ports are DC-coupled 50 Ω interfaces; adding series capacitors degrades return loss and insertion loss above 5 GHz and is not recommended unless absolutely necessary for system-level DC isolation.

Is the HMC136 still in production, and what is its obsolescence status?

The HMC136 is marked OBSOLETE by Analog Devices, with last-time-buy windows closed. Aetrix Electronics maintains legacy inventory sourced from authorized channels with full traceability. No second-source or drop-in replacement exists; design-in should include lifetime buy planning or migration assessment to HMC571 for wider bandwidth or QM11014 for high-volume alternatives.