ISA.50 Passive Mode Antenna Testing

What is the problem or concern we are addressing?

Post-integration optimization of antenna performance through physical and electrical matching as well as orientation and position changes. All antennas are sensitive to their surrounding environment. Once an antenna is integrated into a product it is very common for the exact tuning of the antenna to differ from the design target or development board implementation.

The resonant frequencies for most antennas can be adjusted either by implementing a lumped element electrical matching network, or through small physical modifications to the antenna itself. This tuning effort results in optimal performance of the product as a whole.

The anechoic chambers in our labs are capable of measuring passive-mode antenna performance at any frequency between 400MHz and 6GHz. Our chamber in Enniscorthy, Ireland, can measure between 400MHz and 6GHz, while our chamber in San Diego, California, can measure between 750MHz and 6GHz.

The Processes

Part 1

• Taoglas will modify your prototype device to allow for direct access to the antenna feed point at the beginning of your feed transmission line.
• The antenna will be matched to the desired operational frequencies of the product with all mechanical system elements in place including the enclosure, any batteries, displays or other system elements. The tuning is intended to account for everything in the system in the typical use-case so this includes any human body interaction that would be encountered in certification.
• If the device is worn or held by a person a human body phantom part will be used to account for this.
• Measure radiation pattern and efficiency installed in the device or on the board and in as much as the real use case as possible.
• Complete report detailing test set up, results and conclusion.

What does Taoglas need?

In all cases Taoglas will require the following:
• We will need 2 copies of your device including all the bits and pieces. The units do not need to be fully functional (i.e. firmware/software need not be complete), but they need to be built up representative mechanical samples.
• Things like any battery, LCD display, peripherals,cables,etc.all mounted in some sort of enclosure that’s at least close to what the final enclosure will be like. SLA or FDM proto enclosures are sufficient but the final plastic material can yield slight differences in performance.
• 3D PDF or eDrawing files for your mechanical assembly. We really do need the ability to hide parts, do cross sections and make measurements so an eDrawing with these features turned on is highly recommended.
• Details of any populated matching components or techniques present in the supplied devices.

Part 2

• Taoglas engineering in consultation with the customer on the final report will determine if the measured performance is sufficient for the product to meet its performance and certification requirements.
• If the antenna performance is not acceptable, Taoglas sales and engineering can make recommendations to improve the antenna performance.
• If the antenna performance is acceptable the next step would be active device performance measurements such as TRP, EIRP, TIS or radiated receive sensitivity and RSE testing. Taoglas offers a number of follow-on test services; your Taoglas sales contact can cover all the various options.


Taoglas will compile a report on the antenna measurements including:
• Details of any electrical or mechanical tuning techniques. • Matching network diagram and values.
• Device sample with implemented matching changes.
• Return loss plots of before and after matching.
• Radiation pattern plots for each band.
• Efficiency plots vs. frequency for each band.

* Tuning is not comparable to a custom antenna. It is a simpler onboard or transmission line or cable
modification that can be implemented to improve performance It uses the same antenna part number and avoids new parts that require new design techniques and tooling etc. to implement that part.

**Note that while the device itself may have more than one physical use-case, the tuning of the antenna in this service is limited to a single use-case.

Service Delivery Objectives

A. Antenna installed on a customer device prototype board, with extra antenna prototypes.
B. Matching circuit diagram and documentation of values if relevant (or cable routing diagram, antenna position/mounting etc.).
C. Final antenna position and integration method.
D. Return Loss, VSWR, Average Gain, Efficiency, Peak Gain and Radiation Patterns.
E. Documented performance measurements.