Mr. Mohammad Fakharzadeh Profile

Mohammad Fakharzadeh

at Univ of Waterloo

SPIE Involvement:

Author

Publications (1)

This will count as one of your downloads.

You will have access to both the presentation and article (if available).

DOWNLOAD NOW

This content is available for download via your institution's subscription. To access this item, please sign in to your personal account.

Email or Username Forgot your username?

Password Forgot your password?

Show

Keep me signed in

No SPIE account? Create an account

Proceedings Article | 12 August 2008 Paper

Optical beamforming for retro-directive array antennas

Mohammad Fakharzadeh, Safiedin Safavi-Naeini, Sujeet Chaudhuri

Proceedings Volume 7099, 70991E (2008) https://doi.org/10.1117/12.804733

KEYWORDS: Phased array optics, Antennas, Receivers, Resonators, Phased arrays, Transmitters, Quantization, Waveguides, Phase conjugation, Modulation

Read Abstract +

In this paper we introduce a novel algorithm for the beamforming of a single channel retro-directive phased array system. Retro-directive array antennas are the best candidate for two-way communication, however there must be a large spectral difference between the send and receive carriers to reduce the interference and increase the isolation. When the send and receiver RF frequencies are far apart, e.g. 10 GHz, optical beamforming provides the unique solution to beamforming problem. Moreover single channel array antennas are hardware efficient and cost-effective. The core of the proposed structure is a cascaded ring resonator structure with two parallel waveguides, which can perform the roles of both a tunable optical delay line and a directional coupler. Hence, there is no need to use an optical circulator to separate the reception path from the transmission path. The received RF signal from the antenna is modulated with an optical carrier, ?C, and enters the delay line. The beamforming algorithm calculates the carrier wavelength and the coupling factors between the adjacent rings to maximize the received power from the desired source. Thermo-optics (TO) phase shifters are used to adjust the coupling factors. The algorithm calculates the optimum coupling factors based on the instantaneous feedback from the receiver array, hence it is robust and can compensate for the environmental changes or even the relative motion of the source and antenna platform. The delayed signal that leaves the delay line is demodulated by a photodiode (PD). The RF signal is amplified, filtered and delivered to the base-band receiver for decoding. A sample of the demodulated RF signal is used as the input to the beamforming algorithm to calculate the received power and signal to noise ratio. Based on the time-reversal property of the retro-directive arrays, the same amount of delay is required for the transmitter antenna, so the coupling factors do not need to change.

My Library

You currently do not have any folders to save your paper to! Create a new folder below.

Folder Name

Folder Description

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks. You are receiving this notice because your organization may not have SPIE eBooks access.*

*Shibboleth/Open Athens users─please sign in to access your institution's subscriptions.

To obtain this item, you may purchase the complete book in print or electronic format on SPIE.org.

ORGANIZATIONAL
Sign in with credentials provided by your organization.

Organizational Username

Organizational Password

Show/Hide Password

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members:

Non-members: ADD TO CART

Keywords/Phrases

Search In:

Publication Years