Background Information 

The idea to design and build a microwave anechoic chamber and antenna data acquisition system for teaching and research in the areas of Antennas, EMC, and EMI was actively pursued in the spring semester of 1996. It was decided that the design and construction of the anechoic chamber and antenna data acquisition system shall be accomplished by the students and faculty members of the department of Electrical and Computer Engineering.

 A grant proposal was submitted in the spring semester of 1996 to the College of Engineering and Technology Faculty Research Awards committee seeking funds for the project. The requested grant was awarded. The project was also supported by funds from the department of Electrical and Computer Engineering and Northrop-Grumman Corporation grant.

 Graduate students under the guidance of Dr. Prasad Shastry designed the anechoic chamber. The details of the design of the chamber are documented in the Phase-I report of the project. The Bradley University maintenance and construction crew built the wooden chamber. Dr. Shastry and, his graduate and senior undergraduate students installed the microwave absorbers in the chamber.

 Dr. Prasad Shastry and Dr. Winfred Anakwa jointly advised a graduate student who designed and developed the antenna data acquisition system for the anechoic chamber. Preliminary characterization of the anechoic chamber was also done by the student. The details of the development of the data acquisition system and the characterization of the anechoic chamber can be found in the student's Master's thesis.

Mr. David Miller, Mechanical Shop, College of Engineering and Technology, assisted in the design and construction of the rotating pedestal for the receiving antenna in the anechoic chamber. The project was educational for the students involved. The people who worked on this project and the funding sources have been acknowledged at the end of this page.

 The anechoic chamber and the antenna data acquisition system is being used for instruction in the Microwave and Wireless Engineering laboratory course and, graduate and senior undergraduate capstone projects. For additional details of the anechoic chamber and the antenna data acquisition system,

Dr.Prasad Shastry may be contacted at: snp@bradley.edu.

• Frequency Range: 800 MHz - 30 GHz
• Chamber Dimensions: 9ft * 6ft * 6ft
• Microwave Absorber Thickness: 8 inch & 12 inch

 

			Absorption	at Normal	Incidence	(GHz)
Type	Thickness	Pyramids/Block	0.125	0.250	0.500	1.0	3.0	6.0	10.0	15.0	30.0	Power
AEP-8	8"	64	-	-	-	30	37	45	50	50	50	1W/in.2
AEP-12	12"	36	-	-	-	35	40	45	50	50	50	1W/in.2



• Quiet Zone Dimensions: Minimum 1ft Diameter
• Reflectivity Level within the Quiet Zone: Less than -25dB

Anechoic Chamber Specifications

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Anechoic Chamber Construction
 

Wooden Box for the Anechoic Chamber

Bradley Construction Crew Anechoic Chamber with aluminum exterior

Thirendra and Mike Shover at work -  installing the absorbers

Ali Imran gluing the absorbers

Thirendra cutting the Absorbers

Mike Shover and Thirendra after finishing one wall

Sunil Modur helping with the construction

Dr. Prasad and Thirendra

Ali Imran and Thirendra

Dr. Prasad, Sunil Modur and Thirendra

Construction's Break time

Anechoic Chamber - Transmitting end

Students in RF Lab

Anechoic Chamber - Receiving end

Anechoic Chamber - Transmitting end

back to list Antenna Data Acquisition System The data acquisition system consists of the following: Stepper Motor/NuDrive Amplifier: 52X-411 Encoder: 500 lines of software Pedestal system (includes an RF rotary coupler) HP Signal Generator: E4433B, 250kHz - 4GHz HP Spectrum Analyzer: 8593E, 9kHz - 22GHz LabView version 5.0: National Instruments Gateway 2000 PC HP Printer: DeskJet 695C Antenna Data Acquisition Block diagram Antenna Data Acquisition Flow chart diagram Pedestal System Pedestal System Badria Elnour with Anechoic Chamber's data acquisition H-plane measurement E-plane measurement Horn antenna measurement H-plane measurement E-plane measurement Data Acquisition software main window back to list Anechoic Chamber Characterization Work on the characterization of the anechoic chamber is in progress.  The intent was to measure the capabilities of the anechoic chamber by determining the extent of the quiet zone and other specifications. The radiation characteristics of a horn antenna was measured in the chamber. The radiation pattern predicted by the theory for this antenna was be compared to the measured results. References: [1] Report Anechoic Chamber and Data Aquisition System for the Microwave Engineering Laboratory At Bradley University Bradley University Project Team: Project Director                       :  Dr. Prasad Shastry Graduate Project Assistants   :  Mr. Thirendra Rayamajhi                                                      Mr. Sunil Modur                                                      Mr. Mahmoud Basraoui Phase I Report : System Design ABSTRACT     This report presents the design, specifications and cost estimates of an Anechoic Chamber and Data Acquisition System to be built for instructional as well as research purposes in the Microwave / RF Engineering Laboratory at Bradley University. The report covers the system design efforts during Phase I of the project from June 1996 to May 1997. [2] Thesis Antenna Data Acquisition System and Anechoic Chamber Characterization by :   Badria Elnour Advisor :   Dr. Prasad N.Shastry, Dr. Winfred Anakwa Summer 2003 ABSTRACT    The thesis presents the design of an automated system for the measurements of antenna radiation characteristics in an anechoic chamber. The antenna data acquisition system enables one to plot the radiation patterns of an antenna and determine its important parameters. The thesis further addresses the issues of characterization of the anechoic chamber and presents the results of characterization. back to list   Anechoic Chamber Credits Anechoic Chamber Design & Construction Credits: Mr. Thirendra Rayamajhi Mr. Mahmoud Basraoui Mr. Sunil Modur Mr. Mike Shover Mr. Ali Imran Mr. David Miller Dr. Prasad Shastry Bradley University Facilities Management R & D Grants: CEGT; ECE; Northrop Grumman Corp. Antenna Data Aquisition System Credits: Mr. Ali Imran Mr. John He Mr. Mahesh Naidu Mr. Sameer Naik Ms. Badria Elnour Mr. Sasidhar Vajha Mr. David Miller Dr. Prasad Shastry Dr. Winfred Anakwa R & D Grants: ECE; BU Graduate School; Northrop Grumman Corp. back to list

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