The University of Manchester

ORA for SKA

Prof. A. K. BrownDr. David Zhang

School of Electrical and Electronic EngineeringThe University of Manchester

Email: {anthony.brown, david.zhang}@manchester.ac.uk

The University of Manchester

Outline

A brief review of ORA aperture array antenna design at the end of SKADS

AA-mid Antenna design for PrepSKADiscussions and near future plans

The University of Manchester

Aperture Array Antennas

FLOTT: (a)(d)

BECA: (b)(e)

ORA: (c)(f)

The University of Manchester

23/4/22

Active radiators

The University of ManchesterThe University of Manchester

Three candidate designs for SKADS (16×16 finite arrays)

BECAFLOTT ORA

(Photo Courtesy: SELEX Galileo)

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Active reflection coefficient

0.25 0.4 0.6 0.8 1-35

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0

Frequency (GHz)

Ref

lect

ion

coef

ficie

nt (d

B)

FLOTTBECAORA

The University of ManchesterThe University of Manchester

Cross polarisation in the intercardinal plane at 1 GHz, based on the finite array measurement

0 5 10 15 20 25 30 35 40 45 50 55 60-35

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Angle (deg)

Cro

ss p

olar

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ion

(dB

)

ORAFLOTTBECA

D-plane 45o Cut

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Scanned element pattern for the centre element of the finite array

E-plane, 0o Cut

H-plane 90o Cut

-50 -40 -30 -20 -10 0 10 20 30 40 50-6

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Angle (deg)

Log

Mag

(dB

)

FLOTT, 1 GHz, SimulatedFLOTT, 1 GHz, MeasuredBECA, 1 GHz, MeasuredORA, 1 GHz, MeasuredFLOTT, 700 MHz, Measured

-50 -40 -30 -20 -10 0 10 20 30 40 50-6

-5

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0

Angle (deg)

Log

Mag

(dB

)

FLOTT, 1 GHz, Simulated FLOTT, 1 GHz, MeasuredBECA, 1 GHz, MeasuredORA, 1GHz, MeasuredFLOTT, 700 MHz, Measured

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Change of Frequency Range

LNA integration and feeding methods for ORA

The ORA finite array analysis

Measurement-noise temperature of integrated structure

Manufacturability

The University of Manchester

23/4/22

0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5-45

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Frequency (GHz)

Ref

lect

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coef

ficie

nt (d

B)

Broadside45o E-plane45o H-plane

The infinite ORA array with 125mm element separation

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The infinite ORA array with 112 mm element separation

23/4/22

0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5-35

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Frequency (GHz)

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lect

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coef

ficie

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B)

Broadside45o E-plane45o H-plane

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108mm separation

23/4/22

0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4-40

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Frequency (GHz)

Act

ive

refle

ctio

n co

effic

ient

(dB

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Broadside

45o Diagonal-plane

The University of ManchesterThe University of Manchester

The feeding methods for ORA

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The optimisations of the feeding lines for a lower loss

23/4/22

LNA close to the radiators

For LNA wiring

LNAs above the groundplane

Coaxial cable for single-ended feeding

LNAs below the groundplane, but using coaxial cables for single-ended feedings

Shorter coaxial cables for single-ended feedings

LNA above the groundplane

1 2 3

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Single-ended and differential feeding methods

23/4/22

The single-ended stripline Differential coaxial cable feeding

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ORA performance with 50ohms stripline feed, 112mm

23/4/22

0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5-35

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Frequency (GHz)

Ref

lect

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coef

ficie

nt (d

B)

Broadside45o E-plane45o H-plane

The University of Manchester

23/4/22

0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4-25

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Frequency (GHz)

Ref

lect

ion

coef

ficie

nt (d

B)

Broadside45o E-plane45o H-plane

ORA performance with differential coaxial cable feeds, 112mm element spacing

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Single-ended Stripline feed for the 5×5 subarray of the 10×10 finite array tile

23/4/22

0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4-40

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Frequency (GHz)

Act

ive

refle

ctio

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effic

ient

(dB

)

55 finite array, simulatedinfinite array, simulated55 subarray in a 1010 finite array, measured

The active reflection coefficient

The University of Manchester

Differential feeding method, passive reflection coefficient measured

Element 13

Element 1

0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4-35

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Element 13Element 1

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Integration with EMBRACE front-end electronics for further investigation

23/4/22

The University of Manchester

ORA tile for EMBRACE electronics integration

1375mm

o The element separation of 125 mmo 70 ohms single-ended port for each elemento The coverage area of the tile 1.125 m2

The University of Manchester

• Efficiency measurements• Complete LNA integration and measure

combined noise temperature• Manufacturability design

• EMBRACE compatible tile• Final choice of LNA type and optimise ORA for

mid frequency array• Build and test • Pre-production manufacturing techniques

23/4/22

The University of Manchester

Noise measurement of the active ORA finite array

23/4/22

0.4 0.5 0.6 0.7 0.8 0.9 1-50

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Frequency (GHz)

Ref

lect

ion

coef

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nt (d

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Sub-array becomes active with power splitters

A hot/cold measurement facility is under construction in JBO, the measured results out of this for the finite ORA arrays will be confirmed at THACO in ASTRON

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Further investigation of ORA tile with the EMBRACE electronics ?

23/4/22

1375mm

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The manufacturing cost investigation

23/4/22

Chemical etching: A traditional photo-lithographic technique on PTFE/woven glass laminate

Ink-jet printing: A catalyst is ink-jet printed onto the plastic film, and then copper is electro-formed onto the catalyst, a further electroplating process is required

Screen printing and other technics?

The University of Manchester

• Efficiency measurements• Complete LNA integration and measure

combined noise temperature• Manufacturability design

• EMBRACE compatible tile• Final choice of LNA type and optimise ORA for

mid frequency array• Build and test • Pre-production manufacturing techniques

23/4/22