Test and Measurement Equipment Instrument Selection Informational

How do I select a vector network analyzer for measurements up to 110 GHz?

How do I select a vector network analyzer (VNA) for measurements up to 110 GHz? The VNA is the fundamental RF test instrument for measuring S-parameters, and selecting one for high-frequency work (up to 110 GHz) requires careful evaluation of frequency range, dynamic range, and the waveguide/connector ecosystem: (1) Key specifications: frequency range: 10 MHz-26.5 GHz: covers sub-6 GHz and some FR2. Suitable for most commercial RF work. 10 MHz-50 GHz: covers 5G NR FR2 (24.25-52.6 GHz). 10 MHz-67 GHz: covers the full V-band (57-66 GHz, 802.11ad/ay, radar). 10 MHz-110 GHz: covers the W-band (75-110 GHz, automotive radar at 77 GHz, 6G research). Requires waveguide frequency extenders above 67-70 GHz. Dynamic range: 80-100 dB: adequate for passive components. 110-130 dB: needed for high-isolation devices, multiplexers, amplifiers. 130-145 dB: achievable with high-end VNAs (needed for on-wafer mmWave device characterization). Number of ports: 2-port: sufficient for most 2-port devices. 4-port: needed for differential, multiport, and balanced device measurements. IF bandwidth: 1 Hz to 15 MHz. Narrow IFBW (1-10 Hz) maximizes dynamic range but slows the measurement. Wide IFBW (100 kHz-1 MHz) for fast production testing. (2) Frequency extension: above 67-70 GHz, the VNA uses frequency extender modules (mmWave heads): the VNA itself operates to 67 GHz (coaxial). Frequency extenders multiply the RF and LO signals to reach higher bands. Common extender bands: WR-15 (50-75 GHz), WR-10 (75-110 GHz), WR-06 (110-170 GHz), WR-03 (220-325 GHz). The extender connects to the DUT via a waveguide flange. Major extender manufacturers: Virginia Diodes (VDI), OML, Keysight. (3) Calibration at mmWave: connector type changes with frequency: 1.85 mm (DC-67 GHz), 1.0 mm (DC-110 GHz), waveguide flanges above 67 GHz. Calibration kits are frequency-specific and extremely expensive ($5,000-30,000 per kit). TRL (Thru-Reflect-Line) calibration is preferred at mmWave due to the difficulty of making precision SOLT standards. On-wafer calibration: requires a probe station (Cascade, FormFactor) with GSG probes and impedance standard substrates (ISS). (4) High-end VNA options: Keysight PNA-X N5247B: to 67 GHz, 145 dB dynamic range, NF measurement, gain compression, IMD. With extenders: to 1.1 THz. Price: $150,000-300,000. Rohde & Schwarz ZNA67: to 67 GHz, 140 dB DR, intuitive UI. Price: $120,000-250,000. Anritsu VectorStar MS4647B: to 110 GHz native (no extenders needed). Price: $200,000+. Copper Mountain CobaltFx: to 110 GHz, modular, lower cost alternative ($40,000-80,000).

Category: Test and Measurement Equipment

Updated: April 2026

Product Tie-In: VNAs, Spectrum Analyzers, Signal Generators

VNA Selection for mmWave

Selecting a VNA for measurements up to 110 GHz is a major capital decision, as the instrument and accessories can exceed $500,000 for a complete mmWave measurement setup.

Total Cost of Ownership

(1) VNA instrument: $80,000-300,000. Frequency extenders (pair, WR-10): $40,000-80,000. Calibration kit (1.0 mm or waveguide): $10,000-30,000. Cables (phase-stable, 1.85 mm): $2,000-5,000 each (2-4 needed). Probe station (on-wafer): $50,000-200,000. GSG probes: $5,000-15,000 per probe (2-4 needed). ISS calibration substrate: $3,000-8,000. Total for a complete 110 GHz on-wafer measurement setup: $300,000-700,000. (2) For budget-conscious labs: Copper Mountain modular VNA: significantly lower instrument cost ($40,000-80,000) with comparable performance for many measurements. Refurbished VNAs: Keysight/Agilent PNA-series from 5-10 years ago at 30-50% of new price. Shared facilities: university or national lab measurement services (rental fees $500-2,000 per day). (3) Maintenance: VNA calibration (annual): $3,000-8,000. Cable replacement (connectors wear): $1,000-3,000 per cable.

VNA Selection by Frequency

Sub-6 GHz: VNA to 9/26.5 GHz ($10K-50K)
5G FR2: VNA to 50-67 GHz ($80K-200K)
W-band: VNA to 110 GHz + extenders ($200K+)
Dynamic range: 130-145 dB (high-end)
Calibration: TRL preferred at mmWave

Common Questions

Frequently Asked Questions

Do I need a VNA to 110 GHz?

Only if your work involves: automotive radar at 77 GHz (W-band), 6G research (D-band, 110-170 GHz), or semiconductor device characterization at mmWave. For most commercial RF work: a VNA to 26.5 or 50 GHz is sufficient (covers cellular, Wi-Fi, satellite up to Ku-band). For 5G FR2: a VNA to 50-67 GHz covers the current FR2 bands. The 110 GHz capability is primarily for research, defense, and automotive radar applications.

What connector should I use?

SMA (DC-18 GHz): most common, lowest cost. 3.5 mm (DC-34 GHz): SMA-compatible, higher precision. 2.92 mm/K (DC-40 GHz): for 5G FR2 work. 2.4 mm (DC-50 GHz): for V-band measurements. 1.85 mm/V (DC-67 GHz): for full V-band. 1.0 mm (DC-110 GHz): for W-band. Use the connector that matches your frequency range. Never use a lower-rated connector above its specification (mechanical and electrical damage).

What is the difference between PNA and ENA?

Keysight PNA (Performance Network Analyzer): highest performance, for R&D and advanced measurements. Features: noise figure, active device, pulsed measurements. Keysight ENA (Entry Network Analyzer): lower cost, for component testing and production. Adequate dynamic range for most passive components. The PNA is preferred for: amplifier characterization (NF, compression, IMD), on-wafer measurements, and mmWave work. The ENA is preferred for: filter testing, cable measurements, production environments, and budget-conscious labs.

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