Analog Devices Inc. HMC798ALC4TR

Overview

HMC798ALC4TR from Analog Devices is a GaAs MMIC subharmonic (×2) mixer operating from 24 GHz to 34 GHz, supporting both upconversion and downconversion with integrated LO amplifier, 10 dB typical conversion loss (24–30 GHz), 17.5 dBm input IP3 (24–30 GHz), and dc-to-4 GHz IF bandwidth - deployed in microwave VSAT radios and SATCOM transceivers.

For engineers reviewing the HMC798ALC4TR datasheet, HMC798ALC4TR pinout, HMC798ALC4TR application, or HMC798ALC4TR equivalent, key selection criteria include RF/LO isolation performance across 30–34 GHz, subharmonic LO drive compatibility at 4 dBm, thermal derating above 85°C, and LCC package grounding requirements for mmWave signal integrity.

Technical Context

The HMC798ALC4TR implements a subharmonically pumped (×2) architecture requiring LO input at half the RF frequency (e.g., 12–18 GHz LO for 24–36 GHz RF), eliminating need for high-frequency LO synthesis. Its integrated single-supply LO amplifier operates at 5 V/97 mA and delivers stable gain across temperature.

It supports dual-sideband operation (upper/lower sideband) with dc-coupled IF port (±3 mA max current), ac-coupled 50 Ω LO and RF ports, and 2 × LO-to-RF isolation of 36 dB typical at 30–34 GHz - enabling direct integration into compact mmWave front-ends without external filtering.

Key Specifications

Pinout & Package

RoHS-compliant 24-terminal ceramic LCC package (3.90 mm × 3.90 mm), thermally enhanced with exposed pad requiring RF/dc ground connection. Package type E-24-11 has θ_JA = 120°C/W and θ_JC = 119°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar subharmonic mixer applications.

Compared with HMC1048LC4 and HMC8192LC4, the HMC798ALC4TR provides optimal balance of integrated LO drive, subharmonic simplicity, and E-band isolation - making it preferred for compact, low-SWaP SATCOM and VSAT designs where LO generation complexity must be minimized.

Availability

HMC798ALC4TR is available at Aetrix Electronics and suitable for microwave VSAT radios, SATCOM terminals, military EW receivers, and 5G fixed wireless access systems requiring stable component supply across extended temperature ranges (−40°C to +85°C) and high-reliability mmWave operation.

Supply support for HMC798ALC4TR 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 is a global leader in high-performance analog, mixed-signal, and RF ICs, serving communications, defense, instrumentation, and industrial markets with precision signal processing solutions.

The HMC798ALC4TR belongs to Analog Devices' Hittite Microwave MMIC product line, engineered specifically for millimeter-wave infrastructure applications demanding high linearity, wide IF bandwidth, and simplified LO interface in compact surface-mount packages.

FAQ

What is the recommended LO drive level for HMC798ALC4TR?

The HMC798ALC4TR specifies a typical LO drive level of 4 dBm across its 12–18 GHz LO input range. Operation at 0–6 dBm is supported, with conversion loss and IP3 degrading slightly below 4 dBm and saturating above 6 dBm. The integrated LO amplifier eliminates need for external driver stages, simplifying system design while maintaining consistent performance over temperature (−40°C to +85°C). Always verify LO return loss (>10 dB) at the specific operating frequency using the data sheet's Figure 69.

Can HMC798ALC4TR operate as both an upconverter and downconverter?

Yes, the HMC798ALC4TR supports bidirectional operation: as an upconverter (IF dc–4 GHz → RF 24–34 GHz) and as a downconverter (RF 24–34 GHz → IF dc–4 GHz). Sideband selection (upper/lower) is determined by LO placement relative to RF - low-side LO for upper sideband, high-side LO for lower sideband. Performance metrics such as conversion loss, IP3, and P1dB are specified separately for both modes in the datasheet Tables 1 and Figures 7–62.

What is the maximum allowable IF current for HMC798ALC4TR?

The IF port of the HMC798ALC4TR is dc-coupled and rated for a maximum source or sink current of ±3 mA. Exceeding this limit risks die malfunction or permanent failure. For applications requiring dc coupling, ensure external circuitry (e.g., baseband amplifier or ADC driver) complies with this current constraint. If dc operation is unnecessary, insert a series capacitor sized to pass the required IF band (e.g., 100 pF for 100 MHz–4 GHz) to eliminate dc path entirely.

How should the exposed pad (EPAD) of HMC798ALC4TR be connected?

The exposed pad of the HMC798ALC4TR must be connected to RF and dc ground via a minimum 3×3 array of thermal vias (≥9 vias total) to a solid internal or bottom-layer copper pour. This satisfies JEDEC JESD51-2 thermal guidelines and achieves the specified θ_JA = 120°C/W. Failure to properly ground the EPAD results in elevated junction temperature, degraded conversion loss, and potential reliability issues - especially under continuous operation at +85°C ambient.

Does HMC798ALC4TR require external matching networks on RF or LO ports?

No, the RF and LO ports of the HMC798ALC4TR are internally matched to 50 Ω across their full operating bands (RF: 24–34 GHz; LO: 12–18 GHz), as confirmed by return loss plots in Figures 70 and 69 (typically >10 dB). However, the IF port is dc-coupled and may require external dc blocking if dc operation is not intended. All ports are designed for direct connection to standard 50 Ω transmission lines without discrete matching components.