Overview

The UNI-T UTS3021B Performance-Series Spectrum Analyzer covers 9 kHz – 2.1 GHz with a 10.1-inch capacitive multi-touch display, a 1 Hz resolution-bandwidth floor, and up to 40,001 sweep points. It targets the sub-2.1 GHz bench measurement workload — communications module verification, IoT and wireless development, harmonic and spurious testing — with the option to add a tracking generator in the field when your work demands scalar transmission measurements.

A typical displayed average noise level of -161 dBm/Hz (preamp on) and phase noise of <-98 dBc/Hz at a 10 kHz offset deliver the dynamic range needed for serious signal characterization in the sub-2.1 GHz band. Standard interfaces include HDMI 1.4 display output, USB-A 3.0 (Host), USB-B 2.0 (Device), and Gigabit LAN with full SCPI support — the UTS3021B drops into an automated test rack as easily as it sits on a development bench.

Key Features

UNI-T UTS3021B Details

Frequency Coverage (9 kHz – 2.1 GHz)

The UTS3021B sweeps continuously from 9 kHz up to 2.1 GHz, with 1 Hz frequency resolution and marker counter accuracy on the same order. The 2.1 GHz ceiling covers the 2.4 GHz ISM band's lower edge (with appropriate care near the limit), all sub-GHz ISM bands (315/433/868/915 MHz), common 1.8/2.0 GHz cellular bands, and a comfortable harmonic margin for HF and VHF transmitter work. A 1 Hz frequency reference calibration accuracy with <1 ppm temperature stability keeps measurements steady across the calibration cycle.

Sensitivity (DANL as low as -161 dBm/Hz)

Weak-signal testing depends on how quiet the analyzer itself is. With the preamp on, the UTS3021B reaches a typical displayed average noise level of -161 dBm/Hz in the 200 MHz – 1.5 GHz band — low enough to resolve faint emissions, identify harmonic energy well below the carrier, and characterize signals near the noise floor. Five detector modes (Sample, Peak, Negative, Normal, Average) and four trace types give you the flexibility to tune what the trace shows for any measurement context. A switchable 20 dB preamp adds gain when you need it, and the input attenuator adjusts in 1 dB steps from 0 to 51 dB.

Phase Noise (<-98 dBc/Hz at 10 kHz offset)

Clean local-oscillator performance matters when you're working close to a strong carrier — modulated signal analysis, narrowband interference identification, or oscillator-quality measurement. With typical phase noise of <-98 dBc/Hz at a 10 kHz offset from a 1 GHz carrier (measured with a 1 kHz RBW and 10 Hz VBW), the UTS3021B resolves close-in spectral content without the phase noise pedestal washing it out. Typical performance at a 1 MHz offset is in the -112 to -116 dBc/Hz range — well-suited for general modulated-signal and oscillator work.

1 Hz – 3 MHz Resolution Bandwidth

Resolution bandwidth in 1-3-10 steps, from 1 Hz all the way to 3 MHz, gives you the right sweep speed / selectivity trade-off for any measurement. Drop the RBW to 1 Hz to separate signals closer together in frequency than most mid-tier analyzers can manage; widen it for fast high-level surveys. Bandwidth accuracy holds within 5% nominal, and switching between resolution settings introduces only ±0.2 dB relative amplitude uncertainty. The shape factor (-60 dB / -3 dB ratio) is <4.8:1 nominal — tight skirts that help you separate close-in signals of unequal amplitude. FFT sweep mode is also available for faster narrowband measurements.

40,001 Sweep Points

More points across a trace means finer frequency resolution per pixel and a much better chance of catching signals that fall between coarser bins. The UTS3021B provides up to 40,001 sweep points per trace — four times the count of UNI-T's entry-tier UTS1000B series, and high enough to clearly distinguish closely-spaced signals, identify intermittent emissions, and read marker frequencies with confidence. Combined with six independent traces, you can simultaneously display raw, max-hold, min-hold, and averaged versions of the same span.

10.1-inch Multi-Touch Interface

The UTS3021B uses a 10.1-inch capacitive multi-touch display (1280 × 800 HD resolution) for direct interaction with traces, markers, and menus. Pinch, drag, and zoom directly on the trace; set markers by tapping where you want them; navigate menus the way you'd expect on a modern tablet. For lab environments where a USB mouse or keyboard is more practical, the UTS3021B accepts those through the USB Host port. The touch UI cuts measurement setup time noticeably on day-to-day bench work — especially when you're repeatedly adjusting span, RBW, and marker positions across many sweeps.

Marker Suite (4 Markers, 5 Functions)

Four markers with three modes (Normal, Delta, Fixed) cover the basic measurement vocabulary — reading absolute level, computing delta between two points, locking a marker to a frequency for sweep-to-sweep comparison. Five built-in marker functions go further: Marker Noise reads noise density in dBm/Hz at the marker, Band Power integrates total power over a user-defined band, Band Density reports power per Hz across that band, N dB auto-finds the points N dB down from a peak (useful for measuring -3 dB or -6 dB bandwidths), and Counter reads frequency to 1 Hz resolution.

Connectivity (HDMI, USB, LAN, 10 MHz Ref)

A full set of standard rear-panel interfaces makes the UTS3021B easy to fit into any workflow:

• RF Input: Type-N female, 50 Ω
• HDMI 1.4 display output — mirror the trace to an external monitor for shared review or training
• USB-A 3.0 Host + USB-B 2.0 Device — thumb drive, mouse/keyboard, and SCPI over USB
• LAN VXI-11 (10/100/1000 Base, RJ-45) — networked remote control
• 10 MHz reference in/out (BNC) — lock to an external timebase or share the internal reference
• External trigger input (TTL, BNC, rising/falling edge)

SCPI Remote Control for Automated Test

The UTS3021B responds to industry-standard SCPI commands over both USB-Device (USB-B 2.0) and LAN VXI-11 (RJ-45). That means it drops cleanly into pyvisa, LabVIEW, NI-MAX, or any other test framework that talks to standard instruments — no proprietary protocol layer to learn, no special drivers beyond a USB or LAN connection. Whether you're building a production test rig, automating a parametric sweep across DUTs, or running unattended overnight data collection, the interface scales the same way the rest of the bench does. The full SCPI command set is documented in the UTS3000B Programming Manual.

Tracking Generator Upgrade Path (UTS3000-TG Option)

The UTS3021B chassis is provisioned for tracking generator hardware that you can add in the field by ordering the UTS3000-TG option. The TG range matches the analyzer's frequency: 100 kHz – 2.1 GHz. Output power is adjustable from -40 dBm to 0 dBm in 0.5 dB steps with ±3 dB flatness relative to 50 MHz. Once installed, the TG output appears on its own dedicated front-panel Type-N female 50 Ω connector.

Why this matters: a tracking generator turns the UTS3021B into a scalar network analyzer for transmission measurements. Sweep filters to read insertion loss and frequency response, characterize amplifier gain across a band, measure matching-network response, and check antenna return loss (with a directional coupler) — all without a separate signal generator. Many teams start with the UTS3021B for general spectrum work and add the TG option later when a project demands scalar transmission measurements.

Software Options for Specialized Measurements

The UTS3021B starts as a capable general-purpose spectrum analyzer and grows into specialized roles through software options — the instrument hardware is the same; the options unlock measurement modes:

• UTS3000-AMK (Advanced Measurement Kit) — adds channel power, adjacent channel power (ACP), occupied bandwidth (OBW), time-domain power, carrier-to-noise ratio (CNR), third-order intercept (TOI), and harmonic measurements (up to the 10th harmonic), plus a spectrogram display for time-history visualization
• UTS3000-AMA (Analog Demodulation) — AM and FM demodulation analysis with modulation rate, depth, and frequency offset measurements (20 Hz – 100 kHz modulation rate range)
• UTS3000-EMI (EMI Pre-Compliance) — CISPR-aligned QP/AVG/PEAK detectors, EMI band sweep, and limit-line analysis. Pairs with the optional UTS-EMI01 near-field probe kit (3 mm to 10 cm probes, 30 MHz – 3 GHz) for board-level emission hunting

Built for Working Lab Environments

A spectrum analyzer that lives next to soldering stations, drilling, and general bench work will breathe in dust over time. The UTS3021B addresses this with forced-air cooling and a user-removable dust filter — pop it out, vacuum or blow it off, and slide it back. No tools, no service-center trip, no fan failures from dust accumulation. Operating range is 0 °C to +40 °C, storage to -20 °C / +70 °C, with full ±1 ppm timebase stability across the operational temperature range. The full IEC 61326 EMC compliance and EN 61010 safety qualification (with cETLus mark) round out a unit built to hold up across years of bench use.

RF Design and Validation (sub-2.1 GHz)

Characterize transmit spectrum, harmonics, spurious emissions, and channel power for sub-2.1 GHz designs. The UTS3021B covers all the major sub-GHz ISM bands (315/433/868/915 MHz, LoRa sub-GHz), common 1.8/2.0 GHz cellular bands, and broad harmonic margin for HF/VHF transmitter work. With the AMK option, ACP and OBW measurements add channel-respect verification for designs targeting tight regulatory band edges.

Communications and IoT Module Verification

Production engineering and incoming-inspection workflows for wireless modules — verify TX power, occupied bandwidth, harmonic emissions, and spurious responses against datasheet specs and regulatory limits. SCPI automation lets you build a repeatable production test station around the analyzer, with pass/fail logging against limit lines.

EMI Pre-Compliance Investigation

Catch radiated and conducted emissions issues before sending boards to a full CISPR/FCC compliance lab. With the UTS3000-EMI option plus the UTS-EMI01 near-field probe kit (3 mm to 10 cm probes, 30 MHz – 3 GHz), the UTS3021B becomes a board-level emission hunter — sweep with QP/AVG/PEAK detectors, overlay limit lines, and localize hot spots on the PCB before they cost you a failed compliance test.

Filter and Component Characterization

With the UTS3000-TG option installed, the UTS3021B adds scalar transmission measurements: insertion loss, gain, frequency response, and stopband rejection on filters, amplifiers, attenuators, and antennas. Sweep across 100 kHz – 2.1 GHz and read the response directly on the analyzer trace. Add a directional coupler for return-loss measurements on antennas and matching networks.

Production Test and Quality Control

SCPI automation over USB or LAN (VXI-11) lets the UTS3021B drop into pyvisa, LabVIEW, or NI-TestStand workflows for repeatable production verification. Run end-of-line tests on transmitter modules, RF amplifier gain stages, oscillator output, or filter assemblies; log pass/fail results against limit lines; and feed data into MES or QC databases. Six independent traces, max-hold detection, and 40,001-point sweeps give production-engineering teams the trace depth needed to catch intermittent issues that single-sweep tests miss.

RF Service, Repair, and Maintenance

A capable bench instrument for two-way radio shops, broadcast engineering, antenna service work, and field calibration support. Marker counter functions, harmonic measurements (with AMK), and the touch interface make routine service work quick. The 2.1 GHz ceiling covers commercial broadcast, public-safety and amateur radio, broadcast TV harmonics, and (on 3.6 GHz+ units) sub-6 GHz wireless infrastructure.

Specifications

Accessories and Family Options

Included with Every Unit

• UTS3000B-series Spectrum Analyzer (UTS3021B)
• Power cord
• USB cable (UT-D04)
• English download guide
• Multi-language safety manual
• Factory calibration certificate

Recommended Software Options

• UTS3000-TG — Tracking Generator field-upgrade (100 kHz – 2.1 GHz) for scalar transmission measurements
• UTS3000-AMK — Advanced Measurement Kit (channel power, ACP, OBW, CNR, TOI, harmonics, spectrogram)
• UTS3000-AMA — Analog Demodulation Analysis (AM and FM)
• UTS3000-EMI — EMI Pre-Compliance (CISPR-aligned QP/AVG/PEAK detectors, limit-line analysis)

Recommended Accessories

• UTS-EMI01 Near-Field Probe Kit — Four probes (30 MHz – 3 GHz, 3 mm to 10 cm resolution) for PCB-level emission hunting with the UTS3000-EMI option
• UT-CK01 Utility Kit — SMA/N adapters, cables, and antennas for general RF setup
• UT-W01-6GHz Cable — N-to-N RF cable, 0.7 m, DC – 6 GHz
• UT-W02-6GHz Cable — N-to-SMA RF cable, 0.7 m, DC – 6 GHz

Family Members

• UTS3021B — 2.1 GHz, TG-upgradeable via UTS3000-TG option (this product)
• UTS3036B — 3.6 GHz, TG-upgradeable via UTS3000-TG option
• UTS3084B — 8.4 GHz, no TG
• UTS3084T — 8.4 GHz with integrated tracking generator

Frequently Asked Questions