Contract for the Supply and Installation of a Millimetre-Wave Measurement Facility to the University of Birmingham

Background

The UoB has recently completed construction of a new building for the School of Engineering which includes an anechoic chamber located on the third floor for use by the Communication and Sensing Research Group. The chamber has been outfitted with absorber but currently lacks the hardware (e.g. mechanical stages, RF cables, rotary joints, masts/pedestals etc) and control software required to operate the chamber.

The UoB has recently been awarded funding by the Engineering and Physical Sciences Research Council (EPSRC) to create the Midland's Millimetre-wave Measurement Facility (MMMF). This facility is intended to specialise in free-space measurements across the entire millimetre-wave band, primarily from 1 GHz to 330 GHz. The facility will have a large and varied UK academic and industrial user base and should therefore have versatility and

flexibility at its core.

General Facility Characteristics

The measurement facility realised will support three primary modes of measurement across the frequency range 1 GHz to 330 GHz:

1. Far-field (FF) measurement
2. Spherical near-field (SNF) measurement
3. Variable illumination electromagnetic scattering measurement.

Note that it is accepted that there will be some reduction in mechanical accuracy and precision above 110 GHz due to the reduced wavelength dimensions and mechanical limitations which may impact measurement performance. Appropriate absorber panels/coverings should be supplied to cover equipment when unused for a measurement to maintain the reflection-free environment.

Existing Anechoic Chamber Characteristics

The length, width and height of the anechoic chamber's shielded interior are 10.3m x 6.8m x

3.66m (length, width and height, respectively, not including absorber panels). The chamber

has been outfitted with Wavasorb VHP-12 and VHP-18 absorber. There is a 1.2m by 2.1m door

on the left side of the front of the chamber. There are access panels located in the middle of

the front wall at the bottom and one on the right-bottom side of the front wall.

The chamber is built on a 325 mm thick foundation concrete slab which can be used for attachment of various pedestals and mechanical stages. On top of the concrete slab are 2mm thick hardboard floor sheets and then a 2 mm thick galvanised steel sheeting. The floor sheets are approximately 1.2 m x 2.1 m and held together with 60 mm wide joining strips.

The facility should be designed so that the VNA remains in a fixed location for all measurement modes. This may be either inside the chamber beneath absorber panels and operated remotely, or outside in front of the chamber (the latter is preferred).

Existing RF Hardware

The University of Birmingham has a range of RF equipment for the generation, detection and amplification of microwave and millimetre-wave signals. It is expected that the proposed

equipment will be compatible with as much of this equipment as possible. As a minimum, any proposed solution for each mode of measurement is expected to be compatible with the

listed frequency extender heads to allow measurement above 110 GHz.

Note that there is currently a gap in frequency coverage between 75 GHz and 140 GHz in the listed hardware. The UoB proposes to, independently of this tender, purchase additional frequency extender heads to partially or fully cover this frequency gap. This is likely to be frequency extender heads offered by suppliers Rohde and Schwarz, Keysight or equivalent.

Compatibility with this equipment is important. Any proposed solution should specify compatibility limitations with these proposed RF frequency extender heads.

Building Access

The anechoic chamber is located on the third floor of the School of Engineering building at the University of Birmingham. Access to this floor is provided by an elevator with width,

depth and height of 1310 mm, 2600 mm and 1950 mm, respectively. The elevator has a maximum load capacity of 2000 kg.

Specifications

General

The proposed equipment should be compatible with the existing anechoic chamber as described above.

The rails, masts and turntables should be suitably bolted to the concrete foundation slab of the anechoic chamber.

Far-field Measurement

Capability to make automated, polarisation sensitive far-field antenna measurements from 1GHz to 330 GHz. Below 50 GHz, the measurement will be over 4π steradians and above 50

GHz over 2π steradians.

Motorised azimuthal and polarisation rotation stages for AUT with minimum precision of 0.1 degrees.

Max AUT volume: 55 cm by 55 cm by 55 cm.

Max AUT weight: up to 15 kg (essential) and up to 20 kg (desirable).

Spherical Near-field Measurement (SNF)

Capability to make automated SNF measurement of antennas (co- and cross-pol) from 1 GHz

to 110 GHz over 4π steradians. Provision for SNF measurements from 110 to 330 GHz is highly desirable.

Mechanical positioning accuracy of feed/AUT of 0.02λ (essential) or 0.01 λ (desirable) up to 110 GHz . Best effort beyond 110 GHz.

Angular accuracy minimum precision of 0.1 degrees.

Max AUT volume: 55 cm by 55 cm by 55 cm.

Max AUT Weight: up to 15 kg (essential) and up to 20 kg (desirable).

Electromagnetic Bistatic Scattering Measurement

Capability to make electromagnetic bistatic far-field scattering measurements. It is understood that meeting the far-field requirement will be dependent on the size of the scatterer, gain of the feed antennas and measuring wavelength.

One of the feeds should be mounted on a motorised curved rail providing scattering angle coverage of up to 180° or beyond, to ensure forward scattering measurement capability.

Motorised azimuthal stage for rotating scatterer over 360 degrees with minimum precision of 0.1 degrees.

Polarisation rotation stages on both antenna feeds with minimum angular precision of 0.1 degrees.

Max scatterer weight: 30 kg.

Scatterer maximum size: 1 m by 1 m by 55 cm.

RF Components

All cabling, rotatory joints and any additional internal mixers/amplifiers required for the RF design should be supplied.…