NanoVNA-Program

The MTT-S and AP-S Administrative Committees recently approved a new joint initiative to provide more tangible support to all MTT-S, AP-S, joint MTT-S/AP-S, and their Student-Branch Chapters (hereafter, “Chapters”) worldwide, with educational materials to support students and young professionals in their career development, as well as to inspire greater interest and opportunity for hands-on learning in the areas of RF, microwave, and antenna engineering.

The first phase of this new initiative consists of financial support for all MTT-S and AP-S Chapters in good standing to acquire one or more low-cost portable “nanoVNAs”, which are open-source, handheld, touchscreen, 2-port vector network analyzers available in different configurations and for various frequency ranges (e.g. 10 kHz to 1.5 GHz). This support will also include the acquisition of RF test demo boards that include basic RF components and devices, which may be measured using the nanoVNA (see examples pictured below).

To minimize issues related to shipping, export, and import, Chapters will acquire the kits locally through retailers such as Amazon.com. There will be three mechanisms for financial support to cover the cost of kits based on the number required:

1. MTT-S and AP-S will proactively and automatically issue a supplement of US $100 to each corresponding Chapter’s annual funding request, which is intended to offset the cost of acquiring one kit (any additional costs will be borne by the Chapter).
2. Chapters may request reimbursement for the purchase of up to 2 additional kits at the following link (proof of purchase required). Once approved, they may seek reimbursement from MTT-S or AP-S through their normal channels for Chapter expenses.
3. Chapters may seek reimbursement on behalf of local educational institutions for projects requiring between 3 and 15 kits (e.g. for the purpose of developing a microwave- or antenna-engineering course) at the following link (justification required). Once approved, they may seek reimbursement from MTT-S or AP-S through their normal channels for Chapter expenses.

Financial support for this initiative is limited to 2024 and may be withdrawn at any time.

Projects using Nano-VNAs

1. Cost-effective testing techniques to characterize UHF antennas (Casey Bryant, M.Eng)

Engineers require the ability to measure and characterize the reflection coefficient, gain and patterns of unknown antennas. Due to the cost of antenna measurement facilities and the associated equipment, many tertiary educational institutes do not have these facilities available. The purpose of this research was to investigate the use of a sports field as a testing range with cost-effective equipment. Measurements were conducted at two commercial ranges and a sports field. The first range was an open area test site (OATS) where a cost-effective Nano-VNA was compared to a commercial VNA. The antennas under test were two identical log-periodic dipole arrays with a frequency range from 180 MHz – 3 GHz. Altair FEKO was used to model the antenna and compare results from different ground plane responses. An anechoic chamber was used to make baseline measurements which were then compared to the FEKO simulation, OATS and sports field measurements. The sports field results had close correlation with the anechoic chamber and OATS measurements. The study finds that by using the two antenna method, an antenna can be cost-effectively and reasonably accurately characterized for boresight gain to within 1.7 dB on a sports field. The radiation pattern was also achieved on the sports field to within 3 dB of an anechoic chamber measurement. The results enable students and engineers to take antenna measurements at tertiary institutions.

References:

1. Master thesis: https://etd.cput.ac.za/handle/20.500.11838/3696

2.Journal article: https://ieeexplore.ieee.org/abstract/document/10214186