In order to handle the deep-rooted industrial problem that microwave radar sensor is prone to self-oscillation, vulnerable to interference, and has detection blind area in lighting application, Merrytek launched the antithetical dipoles antenna in 2020, which is believed to be the first of the industry. The antithetical antenna break the above-mentioned bottleneck effectively, realizing microwave radar sensor’s precise detection.

Antithetical Dipoles Antenna: It is a dipole antenna fed by a coupled wire and elevated by a half-wavelength metal conductor in the form of half-separated infeed in the middle.

Antenna is the core component in microwave radar sensor and in charge of signals transmission and reception. Previously, microwave radar sensor usually chooses traditional antenna technologies such as planar antenna and columnar antenna, which have certain limitation in detection area, anti-interference performance, and installation adaptability. It greatly confines sensor’s performance. Now, the antithetical dipoles antenna independently created by Merrytek not only combines the advantages of planar antenna and columnar antenna, but also addresses the key pain point of traditional technologies.

Traditional Antenna VS Antithetical Dipoles Antenna

Planar Antenna

• Back Lobe Influence: There’s interference in its back lobe, but which is relatively lower than that of columnar antenna.

• Detection Blind Area: Evenly distributed radiation eliminates detection blind area.
• Anti-interference Performance: Relatively weak environment adaptability makes it easy to be influenced by wireless signals like 5G and WiFi, contributing to false trigger and self-oscillation.
• Hole Size: The hole size is large, usually 30*20mm. The suitability of fixtures is limited.
• Detection Range: The dependence on the reference ground is large, which will affect the shape of the actual detection area and the coverage area of the detection area under relative conditions.
• Mounting Height: Supports up to 6-8m
• Beam Comparison:

Columnar Antenna

• Back Lobe Influence: It belongs to omnidirectional antenna, having relatively large back lobe where the energy is merely the same as main lobe.

• Detection Blind Area: The polarization pointed by the columnar antenna has a weak electric field and relatively low radiation energy, thus  the antenna almost owns no detection capacity. In other words, a detection blind area exists right in front of or below the installed sensor.
• Anti-interference Performance: Its back lobe is easily affected by interference like metal reflection and object vibration, causing false trigger and self-oscillation.
• Hole Size: The hole size is small, usually φ8mm.
• Detection Range: Because of the detection blind area, the detection range is relatively small.
• Mounting Height: Supports up to 3m
• Beam Comparison:

Antithetical Dipoles Antenna

• Back Lobe Influence: There’s nearly no interference in its back lobe.

• Detection Blind Area: Evenly distributed radiation eliminates detection blind area.
• Anti-interference Performance: There is no back lobe interference. Besides, combined with Merrytek exclusive environment self-adaptive algorithm, it can precisely identify human motion/ minor motion signals, enhancing anti-interference capacity.
• Hole Size: The hole size is small, only 8*20mm.
• Detection Range: Large beam angle makes a relatively large detection range.
• Mounting Height: Supports up to 6m
• Beam Comparison:

Effectively solve the application pain points of traditional microwave sensors:

1. It can maintain normal operation in the closed metal space or iron sheet room and other high reflection harsh application scenarios;
2. The target radiation space is formed in a coupling manner based on duality to avoid forming detection blind areas, which is conducive to improving the effective microwave detection area;
3. It perfectly fits application of fixtures with narrow requirements such as line lights and tri-proof lights.
4. It can adapt to more humid, high and low temperature and other harsh complex environment.

Antithetical dipoles antenna technology is innovative in the industry. It and its related application products have so far obtained over 50 patent authorizations in China, the United States, Australia, and other countries.

Since its introduction in 2020, the antithetical dipoles antenna technology by Merrytek has garnered significant market recognition and remains a mainstream lighting application solution in the industry. To better adapt to various types of lighting applications, Merrytek has developed two product solutions based on the antithetical dipoles antenna technology: a metal bracket product solution and an on-board microstrip product solution, catering to the application requirements of different scenarios.

Metal bracket product solution

• Application Fixtures: Tri-proof lights/strip lights
• Fixture Characteristics: Primarily linear in design, internal space is often limited when configuring microwave sensors, fixture housings mostly made of metal and glass materials, which can easily cause microwave signal reflection.
• Antenna Advantages: Metal bracket antenna with extremely low side lobes, effectively resisting self-oscillation caused by metal reflection.
• Product Characteristics: Antenna bump structure design, offset design, more conducive to narrow boundary installation of fixtures; semi-transparent bump structure, weakening or eliminating shadowing effects.
• Structural Characteristics: New expansion nail installation structure, tool-free and convenient installation.
• Representative Models: MC087D Series；MC098S Series

On-board microstrip product solution

• Application Fixtures: Ceiling lights
• Fixture Characteristics: Ultra-thin structure, limited internal space, fixture housings mostly made of plastic, metal, glass, and ceramic materials, which can easily cause microwave signal reflection.
• Antenna Advantages: Ultra-low side lobe miniature on-board microstrip antenna, effectively resisting self-oscillation caused by metal reflection.
• Product Characteristics: Ultra-thin and elongated form, strong versatility; miniature bump structure, reducing the exposed projection area of the antenna, weakening or eliminating shadowing effects.
• Structural Characteristics: New snap-fit installation structure, tool-free and convenient installation.
• Representative Models: MC130S Series；MC131D Series；MC137D Series

As a technology-driven enterprise with innovation at its core, Merrytek is consistently dedicated to addressing the pain points and challenges within the industry. Adhering to a “people-oriented” approach, the company continuously optimizes product performance and user experience from the perspective of actual user needs, while also striving to reduce usage costs. This commitment underscores Merrytek’s philosophy of making advanced technology accessible and beneficial to all.