Dual polarized probes for modern high precision measurement systems have strict requirements in terms of pattern shape, polarization purity, return loss and port-to-port isolation. A desired feature of a good probe is that the useable bandwidth should exceed that of the antenna under test so that probe mounting and alignment is performed only once during a measurement campaign. As a consequence, the probe design is a trade-off between performance requirements and the usable bandwidth of the probe. A new probe technology has been developed capable of achieving 1:4 bandwidth while maintaining the high performance of traditional probe designs [1-4]. This paper describes the new probe technology and discusses the application of these probes in spherical near field and traditional far field measurement systems.

http://ap-s.ei.tuat.ac.jp/isapx/2008/pdf/1645432.pdf

Wide band dual polarized probes for near and farfield measurement systems

Recent advances in the design of orthomode junctions (OMJs) have created new devices capable of achieving as much as a 1:4 bandwidth, while maintaining the high performance of traditional OMJ designs. The new OMJ technology is based on an inverted-ridge structure, with four symmetrical feeding points for external balanced feeding, stabilizing the frequency dependence of the OMJ. This paper discusses the achievable performance and limitations of wideband probes with multiple corrugated apertures. It shows measured and predicted design examples of apertures covering up to 1:2 bandwidth in the L- to Ka-band range.

Dual-Polarized Corrugated Horns for Advanced Measurement Applications

The development, manufacturing and test of dual circular polarized probes with up to 1:2 bandwidth has been discussed. Preliminary measurements with “ideal” BFN show that the design is compliant with the specification.

High accuracy field probes in circular polarisation

Dual-polarized probes with wide-bandwidth operational capabilities are highly desirable for time-efficient Planar Near-Field (PNF) measurements [1]-[3]. However, sometimes the performance tradeoffs necessary to achieve the desired operating bandwidth make such probes impractical for many applications. Traditional probes are often bandwidth limited, and their electrical size can be an undesired source of scattering in PNF measurements, in particular if the probe-AUT distance is small [4]-[5]. An innovative, octave-band probe has recently been presented combining wide bandwidth, near constant directivity, low cross-polarization, and minimum scattering [6]. In this paper, the probe design is discussed in detail, including technical and implementation trade-offs. Several probes have been manufactured at L/Ku-band band, and test results are presented. The probe design is fully scalable, even beyond Ka-band. The scattering properties of the probe (in terms of measurement perturbation) are assessed by numerical simulation and compared to standard rectangular open-ended waveguides.

Dual-polarized probe with full octave bandwidth and minimum scattering for planar near field measurements

Dual polarized probes for modern high precision measurement systems have strict requirements in terms of pattern shape, polarization purity, return loss and port-to-port isolation. A desired feature of a good probe is that the useable bandwidth should exceed that of the antenna under test so that probe mounting and alignment is performed only once during a measurement campaign [1]. As a consequence, the probe selection/design is a trade-off between performance requirements and the usable bandwidth of the probe. Recently, a new orthomode junction (OMJ) and probe technology has been developed capable of achieving as much as 1:4 bandwidth while maintaining the high performance standards of traditional probe designs [2–9]. An example of a field probe based on this technology is shown in Figure 1. The development, test and performance details of these probes has been reported in [7]. At the lower frequencies the aperture diameter of these probes is about 0.7λ making them highly useful for any measurement application. However, the aperture diameter in terms of wavelengths increases with frequency and becomes close to 3λ on a 1:4 frequency range.

Wideband dual polarized probe with interchangeable apertures for advanced antenna measurement applications

Wide-band, dual polarized probes based on an innovative self-balanced feeding scheme has been developed for high accuracy near field measurements. The innovative self-balanced feeding gives a reduction in cost and complexity while maintaining high performance standards. The overall simplicity makes the new technology attractive for probe designs in the L to Ka band range.

A. Giacomini

Papers

Wide-band dual polarized probes for near field antenna measurements