I. Technical Positioning and Core Functions

　　In radio frequency (RF) test equipment, the microwave power divider is a core passive device for accurate signal distribution and comparison, primarily undertaking three core tasks:

　　**Test Signal Distribution:** Distributing standard signals from vector signal sources and microwave signal generators evenly to multiple devices under test (DUTs) (such as amplifiers and filters), enabling multi-port synchronous testing;

　　**Comparison and Measurement Adaptation:** In calibration systems, distributing reference signals to standard instruments and DUTs (such as modulation analyzers) to complete traceability comparisons of parameters such as amplitude and phase;

　　**Multi-channel Signal Synthesis:** At the receiving end, aggregating multiple DUT signals to devices such as vector network analyzers, improving test efficiency.

　　**Its operating frequency band must cover the commonly used microwave/millimeter-wave range of test equipment (typically 10MHz-500GHz), and it must meet the stringent requirements of the test scenario for signal consistency and stability.

　　** II. Key Requirements for Adapting to RF Test Equipment

　　**High-Precision Amplitude and Phase Consistency**

　　In multi-channel testing, the amplitude imbalance of each output port of the power divider must be controlled within ±0.1dB, and the phase imbalance ≤2° (e.g., 1-6GHz band). Otherwise, the accuracy of the test results will be directly affected. For example, in 5G component testing, a phase deviation exceeding 3° will increase the EVM measurement error by more than 15%.

　　**High Power Capacity and Low Loss Balance**

　　When testing high-power devices such as power amplifiers, the power divider needs to withstand 1W-1kW power (watt-level to kilowatt-level) while maintaining an insertion loss ≤0.3dB (ideal state). Using waveguide structures or thick copper foil microstrip line designs can achieve a balance between power capacity and low loss. For example, the WR-42 waveguide power divider can withstand 50W of power in the 18-26.5GHz band with an insertion loss of only 0.2dB.

　　Wide Bandwidth and High Isolation

　　To adapt to multi-band testing requirements, the power divider must possess ultra-wideband characteristics, with a relative bandwidth typically ≥50%, and in some scenarios, coverage of the entire DC-125GHz band. Simultaneously, port isolation must be ≥25dB to prevent signal crosstalk between devices under test from causing test distortion, which is especially crucial in multi-port module testing.

　　Calibration Compatibility

　　The power divider must support traceability adaptation with power reference devices. For example, in coaxial power calibration, the impedance matching error of the power divider must be ≤0.1% to ensure accurate power value transfer from the DC standard to the microwave frequency band.

　　III. Core Design Technologies and Optimization Directions

　　Topology Selection

　　High-Precision Testing Scenarios: An improved Wilkinson power divider structure is adopted, with multi-section impedance transformation networks enhancing isolation (≥30dB) and optimizing resistive load layout to reduce phase deviation, adapting to precision measurements such as modulation calibration.

　　High-Power Testing Scenarios: A waveguide branch-type power divider is employed, utilizing fan-shaped branches to broaden bandwidth (e.g., 1-18GHz coverage), while a metallic waveguide structure improves power tolerance.

　　Multi-Channel Testing Scenarios: A tree-cascaded structure is adopted, combined with a tapered line matching design, to control the VSWR below 1.1, adapting to the multi-port testing requirements of vector network analyzers.

　　Materials and Process Optimization

　　The substrate uses ultra-low loss ceramic material (loss tangent tanδ≤0.0005), combined with a gold-plated metal layer (thickness ≥35μm), reducing signal transmission loss and temperature drift.

　　High-power models employ oxygen-free copper waveguide cavity technology, with inner wall polishing precision reaching Ra0.1μm, reducing conductor loss and adapting to 100-watt power testing scenarios.

　　Calibration and Adaptor Design

　　Standard calibration interfaces (such as 3.5mm and 2.4mm coaxial interfaces) are integrated into the power divider input port, supporting direct interface with power transfer standards and enabling real-time correction of test errors. For example, in the 26.5-110GHz frequency band, power measurement uncertainty can be reduced to 0.8%-2.0% (k=2) through calibration and adaptation.

　　IV. Typical Application Scenarios

　　**Modulation Calibration System**

　　In the modulation standard device, a two-part Wilkinson power divider is used to distribute the output of the modulation signal generator to the standard modulation analyzer and the device under test (DUT). Amplitude/phase consistency ensures the calibration accuracy of parameters such as modulation depth and frequency offset. The measurement process can be fully automated.

　　**Multi-channel 5G Component Testing**

　　In the microwave probe station test platform, a four-part wideband power divider (covering 1-40GHz) distributes the vector signal source signal to 8 DUT MMIC chips. Combined with a high isolation design (≥28dB), crosstalk between chips is avoided, enabling parallel testing of S-parameters and power characteristics.

　　High-Power Device Testing

　　In the testing of kilowatt-level power amplifiers, a waveguide-type unequal power divider (power distribution ratio 1:10) is used to send the main high-power signal to the amplifier under test, while the branch small signals are sent to the power meter for monitoring. This satisfies the high power tolerance requirements and enables real-time power traceability during the testing process.

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