ESJ Technology | RF Microwave mmWave Components Manufacturer

About ESJ Technology

ESJ Technology Co., Ltd was established in 2015 in Shenzhen, China. We are a professional manufacturer specializing in RF Microwave Components, including Power Dividers, Fixed Attenuators, Coaxial Circulators/Isolators, Coaxial Adapters, Directional Couplers, Hybrids, Filters, and Cable Assemblies.

Our components are widely used in military, aerospace, defense, telecommunications, and 5G applications. With exports to over 20 countries, we have received excellent feedback from valued customers around the globe.

High Performance & Quality

Engineered for reliability in extreme environments.

Fast Delivery Time

Efficient production and global logistics network.

Customized Solutions

Tailored RF components based on customer specifications.

What We Do

We manufacture high-precision RF microwave components used in telecommunications, base stations, military, aerospace, and defense applications.

RF & Microwave Design

Advanced simulation and modeling for optimal signal integrity and performance across wide frequency bands.

Quality Assurance

Rigorous testing protocols ensure every component meets international standards including RoHS compliance.

Custom Manufacturing

From concept to production, we deliver bespoke RF solutions tailored to your system requirements.

Key Applications

Base Stations

High-reliability components for 4G/5G macro and small cell infrastructure with excellent VSWR and low insertion loss.

Telecommunications

Broadband RF solutions for signal routing, monitoring, and amplification in core and edge networks.

Defense & Aerospace

Ruggedized components designed for radar, EW, SATCOM, and avionics systems operating in harsh environments.

Our Products

1.85mm Inner DC Block

Frequency Range: 0.01–67 GHz

• Low Insertion Loss
• High Power Handling
• Precision Coaxial Design

1W Fixed Attenuator

Up to 110 GHz

• Ultra-Wideband Performance
• Excellent VSWR
• RoHS Compliant

Directional Coupler

Up to 67 GHz

• High Directivity
• Tight Coupling Tolerance
• Ideal for Signal Monitoring

2W Fixed Attenuator

Up to 67 GHz

• High Power Rating
• Stable Over Temperature
• Repeatability Across Batches

VNA Test Cable

With Armor Protection

• Phase & Amplitude Stability
• Flexible & Durable
• Ideal for Lab & Field Use

Band Pass Filter

Customizable Frequency Bands

• Sharp Roll-Off
• Low Passband Ripple
• High Rejection Outside Band

2-Way Power Divider

Up to 50 GHz

• Equal Power Split
• Low Amplitude Imbalance
• High Isolation Between Ports

2.4mm Inner DC Block

0.01–50 GHz

• Precision Milling
• Low Reflection
• Ideal for mmWave Systems

RF Circulator

Coaxial, 3-Port

• High Isolation
• Low Insertion Loss
• Used in Radar & Duplexers

RF Isolator

Protects Sensitive Equipment

• Non-Reciprocal Transmission
• High Power Handling
• Minimizes Reflection Damage

RF Cable Assemblies

Various Connectors & Lengths

• Phase-Stable Options
• Low PIM Versions Available
• Custom Configurations

Hybrid Coupler

90° or 180° Phase Shift

• Balanced Signal Distribution
• Used in Phased Arrays
• High Port-to-Port Isolation

Why Choose ESJ Technology?

RoHS Compliant Manufacturing

All products meet environmental and safety standards for global markets.
Global Customer Support

Serving over 20 countries with responsive technical and sales teams.
Fast Time-to-Market

Efficient R&D and production cycles ensure rapid delivery of prototypes and volume orders.

2015

Founded in Shenzhen

20+

Countries Served

110

GHz Max Frequency

100+

Custom Projects Delivered

Latest News

110GHz Ultra-Wideband Attenuator Launches

Ushering in a new era of millimeter-wave and terahertz applications with unmatched bandwidth and stability.

August 6, 2025

New Product

Power Divider Principles, Types, and Core Applications

Deep dive into power divider technologies in 5G, radar, and other critical RF systems.

July 31, 2025

Industry Insight

Application of 300–700MHz RF Amplifiers

Key technology analysis for public safety, LTE, and broadband wireless systems.

July 10, 2025

Technical

Customized Dual Junction Circulator

Delivered for a defense client requiring high-power handling and dual-band operation.

August 14, 2023

Custom Project

RF, Microwave & mmWave Components Manufacturer