Your Content Goes Here

Features & Performance Characteristics

Broadband Coupling Performance

The 559 Series Broadband Directional Couplers utilize a broadwall multi-hole waveguide design to provide controlled and consistent coupling across the operating frequency band. This makes the series well suited for broadband microwave and millimeter-wave test, measurement, and system integration applications.

Controlled RF Power Sampling

The 559 Series provides an efficient method for sampling a defined portion of RF power traveling through the main waveguide path. The coupled signal can be routed to detectors, power meters, analyzers, or other measurement equipment while allowing the primary signal to continue through the system.

RF Signal Injection

In addition to signal sampling, the directional coupler can be used to introduce a controlled RF signal into the main transmission path. This capability is useful for calibration, system testing, signal monitoring, and other RF instrumentation applications.

Wide Range of Coupling Values

Standard coupling configurations include:

• 3 dB
• 6 dB
• 10 dB
• 20 dB
• 30 dB
• 40 dB
• 50 dB

This broad selection allows engineers to choose an appropriate coupling level based on the amount of RF energy required at the coupled port.

Multi-Hole Directional Coupling

The broadwall multi-hole coupling structure provides controlled energy transfer between the main waveguide and coupled path. The design supports broadband directional performance while helping minimize unwanted interaction between ports.

Low Main-Line Signal Disruption

The coupler is designed to sample RF energy without unnecessarily disturbing the primary transmission path, helping preserve signal integrity throughout the RF system.

Precision Waveguide Construction

Precision-machined waveguide structures and mating surfaces help minimize discontinuities, reflections, and unwanted losses while providing repeatable mechanical and RF performance.

Flexible Test & Measurement Integration

With coupling values ranging from 3 to 50 dB, the 559 Series can support applications ranging from relatively high-level signal coupling to low-level monitoring and measurement.

Microwave & Millimeter-Wave Applications

The waveguide construction makes the Series 559 suitable for high-frequency systems including radar, communications, RF test equipment, laboratory instrumentation, component characterization, and microwave or millimeter-wave subsystem development.

Custom Configurations Available

Custom coupling values, frequency ranges, waveguide sizes, flange interfaces, and mechanical configurations can be developed to meet specialized RF system and test requirements.

Applications

RF Power Monitoring & Measurement

Mi-Wave’s 559 Series Broadband Directional Couplers provide a convenient method for sampling a controlled portion of RF energy traveling through a waveguide system. The coupled signal can be routed to power meters, detectors, spectrum analyzers, or other instrumentation for system monitoring, calibration, and performance verification.

RF Test & Measurement Systems

Broadband directional couplers are widely used in laboratory and production test environments where engineers need access to a representative sample of the main RF signal without significantly interrupting the transmission path.

Typical applications include:

• RF power measurement
• Signal monitoring
• Network and spectrum analysis
• Component characterization
• Calibration systems
• Automated RF testing
• Laboratory instrumentation

Test Signal Injection

The Series 559 can also be used to inject a controlled RF signal into a transmission line. This makes the coupler useful for calibration, system verification, troubleshooting, and applications where an auxiliary signal must be introduced into an existing RF path.

Radar Systems

Directional couplers can be integrated into radar transmit and test architectures to provide controlled signal samples for monitoring and measurement.

Typical applications include:

• Transmitter power monitoring
• Radar subsystem testing
• Calibration signal injection
• RF chain characterization
• Laboratory radar development

Communication Systems

In microwave and millimeter-wave communication systems, directional couplers provide access to the RF signal for monitoring and testing while allowing the primary communication signal to continue through the main waveguide path.

Applications include:

• Microwave communication links
• Millimeter-wave links
• Ground communication equipment
• Transmitter monitoring
• RF subsystem verification

Satellite Communications (SatCom)

The Series 559 can be incorporated into satellite communication ground equipment and RF test systems where controlled signal sampling or injection is required for system monitoring, alignment, calibration, or troubleshooting.

Amplifier & Transmitter Testing

Directional couplers can provide a reduced-power sample of high-level RF signals, allowing measurement equipment to monitor amplifier or transmitter output without being directly exposed to the full main-line power level.

This is useful for:

• Power amplifier testing
• Transmitter characterization
• Output power monitoring
• RF system diagnostics
• Production testing

Microwave & Millimeter-Wave R&D

The broad coupling range of the Series 559 makes it useful for experimental RF setups and research environments where engineers need flexible access to signals within a waveguide transmission system.

Typical uses include prototype evaluation, component development, high-frequency measurements, system characterization, and experimental RF signal injection.

Custom RF Subsystems

Mi-Wave can integrate directional coupling into larger microwave and millimeter-wave assemblies. Custom frequency ranges, coupling levels, waveguide sizes, flange interfaces, and mechanical configurations can be developed for specialized commercial, aerospace, defense, and research applications.

Applications

Power Monitoring & Measurement

Bi-directional couplers are widely used to sample forward and reflected power in RF systems for power monitoring, calibration, and performance verification.

VSWR & Return Loss Measurement

Because the coupler samples both incident and reflected signals, it can be used to evaluate impedance matching, reflected power levels, and overall transmission line performance.

Balanced Mixer Systems

3 dB couplers are commonly integrated into balanced mixer architectures where broadband RF and LO power division is required.

Radar & Electronic Warfare Systems

Couplers support signal routing, monitoring, calibration, and subsystem integration in advanced radar and EW platforms.

RF & Microwave Test Systems

Used in laboratory environments for:

• Signal monitoring
• Network analysis
• Component characterization
• Automated RF testing

Satellite & Communication Systems

Bi-directional couplers are used in communication links where monitoring forward and reflected RF power is necessary for maintaining link stability and system efficiency.

Glossary of Broadband Directional Coupler Terms

Broadband Directional Coupler

A passive RF component designed to sample a controlled portion of electromagnetic energy traveling through a transmission line while allowing the primary signal to continue along the main RF path.

Directional Coupling

The controlled transfer of RF energy from the main transmission line to a coupled port, with preferential coupling based on the direction of signal propagation.

Coupling Value

The difference, expressed in decibels (dB), between the power traveling through the main transmission line and the power available at the coupled port. Mi-Wave’s 559 Series is offered in standard 3, 6, 10, 20, 30, 40, and 50 dB coupling values.

Coupled Port

The secondary RF port where a controlled sample of the main-line signal is available for measurement, monitoring, or other system functions.

Main Line

The primary waveguide transmission path through which the majority of the RF power travels.

Through Port

The output of the main transmission path where RF energy continues after passing through the directional coupler.

Input Port

The waveguide port through which RF energy enters the main transmission path of the coupler.

Directivity

A measure of how effectively a directional coupler distinguishes between RF energy traveling in opposite directions. Higher directivity helps reduce unwanted signal contributions at the coupled port.

Insertion Loss

The amount of RF signal power lost in the main transmission path as a result of inserting the directional coupler into the system.

Broadwall Coupler

A waveguide directional coupler in which electromagnetic energy is coupled through apertures located along the broad wall of the waveguide.

Multi-Hole Coupling

A coupling technique that uses multiple precisely positioned apertures between waveguide sections to provide controlled energy transfer and broadband directional performance. The 559 Series utilizes a broadwall multi-hole design.

Broadband Operation

The ability of a component to maintain useful RF performance across a relatively wide frequency range rather than being optimized for only a narrow portion of the spectrum.

RF Power Sampling

The process of extracting a known portion of RF energy from a transmission line so that the signal can be measured or monitored without directly routing the full main-line power into the measurement equipment.

Signal Injection

The process of introducing a controlled RF signal into an existing transmission line through the coupled path of a directional coupler.

Coupling Factor

A measurement, normally expressed in dB, describing the relationship between main-line RF power and the power delivered to the coupled port.

3 dB Coupling

A coupling condition where a relatively large portion of the input RF power is transferred to the coupled path. It can be useful in applications requiring substantial power division.

20 dB Coupling

A commonly used coupling level for RF monitoring and measurement where only a small portion of the main-line signal is required.

30–50 dB Coupling

Higher coupling-factor configurations that provide progressively smaller samples of main-line RF power, useful when monitoring higher-power signals with sensitive measurement equipment.

Waveguide

A conductive transmission structure used to guide electromagnetic energy, particularly at microwave and millimeter-wave frequencies.

Waveguide Directional Coupler

A directional coupler constructed as part of a waveguide transmission system for controlled sampling or injection of microwave and millimeter-wave signals.

Waveguide Size

The standardized physical dimensions of a waveguide selected according to the intended operating frequency range.

Waveguide Flange

The mechanical interface used to connect the directional coupler to adjoining waveguide components.

Impedance Matching

The process of minimizing impedance discontinuities between RF components to reduce unwanted reflections and improve power transfer.

VSWR

Voltage Standing Wave Ratio is a measure of impedance matching within an RF transmission system. Lower VSWR generally indicates lower reflected power and a better impedance match.

Return Loss

A logarithmic measurement, expressed in dB, describing the amount of RF energy reflected because of an impedance mismatch.

Reflected Power

RF energy traveling back toward the source because of an impedance mismatch or discontinuity elsewhere in the transmission system.

Incident Power

RF energy traveling from the source toward the load through the main transmission path.

RF Power Monitoring

The process of continuously or periodically measuring RF signal levels to verify transmitter, amplifier, communication, or subsystem performance.

Power Handling

The maximum RF power that a coupler can safely accommodate while maintaining its specified electrical and mechanical performance.

Microwave

A portion of the RF spectrum commonly associated with frequencies from approximately 1 GHz to 30 GHz.

Millimeter-Wave (mmWave)

The frequency range generally spanning approximately 30 GHz to 300 GHz, where waveguide components are widely used for low-loss RF transmission.

RF Test & Measurement

The use of instruments and RF components to measure parameters such as power, frequency response, insertion loss, return loss, and other characteristics of microwave and millimeter-wave systems.

Calibration

The process of comparing or adjusting a measurement system against a known reference. Directional couplers can provide controlled signal sampling or injection for RF calibration setups.

System Characterization

The process of measuring and evaluating the electrical performance of an RF component, subsystem, or complete signal chain under defined operating conditions.