Compared to other RF spectrum measurement technologies, millimeter-wave (mmWave) is relatively new. This band of spectrum is between 30 GHz and 300 GHz, and is being used by many researchers to test 5G wireless broadband. Millimeter-wave testing (namely network analysis) is capable of various improvements in accuracy, test plans, measurement configuration, and cost-effectiveness. With insight provided by Keysight Technology there are five solutions potentially capable of improving mmWave testing and network analysis, many of which are featured in their N5290A and N5291A broadband network analyzer models.
1. Ensuring results are accurate and repeatable
While it can be challenging and time-consuming, assembling a “roll your own” mmWave network analyzer offers no guaranteed specifications for stability or accuracy. One viable alternative involves a preconfigured solution that features a two- or four-port network analyzer, along with necessary millimeter-wave cabling, frequency extenders, and test-set controller.
Keysight’s N5290/91A solutions, for example, enable researchers to either select a PNA or PNA-X network analyzer, and can reach maximum frequencies of 26.5 GHz or 67 GHz. In addition, the N5290/91A solution is also compatible with wafer-level measurement solutions (WMS) to further ensure accurate and repeatable on-wafer results. As a result, you have broad millimeter-wave solutions become capable of enhancing device characterization and modeling for on-wager and connectorized measurements.
2. Better accuracy through calibration
According to Keysight, devices like their aforementioned broadband millimeter-wave network analyzer models help ensure better results across the entire frequency range (which is between 900 Hz and 120 GHz) of a researcher’s design, using improved calibration. As a continued example, the calibration process for Keysight’s N5290 and 91A analyzers utilize an improved-accuracy database that supports 1.0 mm calibration and verification kits.
These kits, along with DC-to-120 GHz power sensors offer traceable measurements, which reduce uncertainty using accurate characterizations of residual calibration errors. Incorporating automatic fixtures ensure more accurate calibration at probe tips, along with improving the clarity of on-wafer measurement readings. Ruggedized 1.0 mm test ports are included in companion compact frequency-extender modules to ensure repeatable connections from one measurement onto the next, which reduces calibration uncertainty and further enhances system-level measurement precision.
3. Accelerating complex test plans
Next-generation monolithic microwave integrated circuits (MMICs) feature components that operate at baseband, RF, microwave, and millimeter-wave. With single-sweep coverage from hertz to gigahertz, vector network analyzers (VNAs) enable you to test these components in a single test setup.
It’s inconvenient to connect, disconnect, and reconnect an MMIC to multiple analyzers, making single-connection, multiple-measurement (SCMM) architecture of a VNA a viable solution. Using one set of connections, SCMM allows you to measure S-parameters, noise figure, gain compression, THD, IMD, and spectrum analysis in passive or active devices for PNA-X. In addition, testing I/Q modulators, converters, along with differential mixers and amplifiers help simplify testing through control of source phase and frequency.
4. Simplifying Measurement Configuration
Certain network analyzer software tools can help achieve deeper insights into device performance, helping save time and ensuring the correct configuration of complex tasks. Scalar mixers and/or converters, for example, support scalar characterization of mixers and frequency converters.
Amplifiers and frequency converters are provided with a complete and enabled characterization using gain-compression and noise-figure, while testing of devices like amplifiers and mixers are simplified using differential and I/Q devices. A spectrum analyzer provides calibrated multi-channel analysis of the spectrum, while touch-enabled applications can offer more intuitive ways of investigating, characterizing, and troubleshooting broadband millimeter-wave devices.
5. Testing Cost-Efficiency
To start, widening frequency coverage helps with reducing test solution costs. A starting frequency of 900 Hz in a millimeter-wave network analyzer, for example, eliminates any need to purchase a dedicated low-frequency VNA. Moving a DUT between fewer test stations, boosts yield by reducing the likeliness of damage by using one analyzer to mitigate complexity, which is done through streamlining the development of test system software.
Other methods of further reducing test costs include optimizing the calibration process, which starts with the ability of maintaining a single calibration across numerous setups. Having said that, this requires impeccable stability in the test system over a lengthy period of time during the entire test cycle of production run. In Keysight’s N5290/91A, for example, their “cal all” feature enables the user to perform and apply one calibration to multiple measurement setups.