Cached at:
07/06/26, 11:07 PM
# Rotman lens
Source: [https://en.wikipedia.org/wiki/Rotman_lens](https://en.wikipedia.org/wiki/Rotman_lens)
From Wikipedia, the free encyclopedia
[](https://en.wikipedia.org/wiki/File:Rotman_lens.jpg)A[microstrip](https://en.wikipedia.org/wiki/Microstrip)implementation of a Rotman lensA**Rotman lens**\(sometimes referred to as a**Rotman\-Turner lens**\) is a[passive electronic component](https://en.wikipedia.org/wiki/Passive_electronic_component)used for[beamforming](https://en.wikipedia.org/wiki/Beamforming)in[radio frequency](https://en.wikipedia.org/wiki/Radio_frequency)applications\. The principle was first published by[Walter Rotman](https://en.wikipedia.org/wiki/Walter_Rotman)and R\. F\. Turner in 1963,[\[1\]](https://en.wikipedia.org/wiki/Rotman_lens#cite_note-1)and patented by Rotman the same year\.[\[2\]](https://en.wikipedia.org/wiki/Rotman_lens#cite_note-2)
[](https://en.wikipedia.org/wiki/File:Rotman_lens_diagram.png)Beam, array and dummy ports on a Rotman lensThe component allows multiple antenna beams to be formed without the need for[phase shifters](https://en.wikipedia.org/wiki/Phase_shift_module)\. It consists of a range of input ports \(also called beam ports\) and output ports \(also called array ports\)\.[\[3\]](https://en.wikipedia.org/wiki/Rotman_lens#cite_note-:0-3)A signal applied to one of the input ports arrives at each of the output ports with a different[phase shift](https://en.wikipedia.org/wiki/Phase_(waves)#Phase_shift)\. If the output ports are connected to individual antennas in an[antenna array](https://en.wikipedia.org/wiki/Antenna_array), this allows shaping the beam in different directions by switching which input port the signal is sent to\.[\[4\]](https://en.wikipedia.org/wiki/Rotman_lens#cite_note-4)So\-called dummy ports can be added to the design, which are[terminated](https://en.wikipedia.org/wiki/Electrical_termination)to absorb fields that hit them, thus preventing reflections from the side wall of the lens\.[\[3\]](https://en.wikipedia.org/wiki/Rotman_lens#cite_note-:0-3)[\[5\]](https://en.wikipedia.org/wiki/Rotman_lens#cite_note-5)
Rotman lenses can be constructed either from hollow conductive[waveguides](https://en.wikipedia.org/wiki/Waveguide)or on a[stripline](https://en.wikipedia.org/wiki/Stripline)or[microstrip](https://en.wikipedia.org/wiki/Microstrip)substrate\. They are commonly used for beamforming in[radar](https://en.wikipedia.org/wiki/Radar)applications\.[\[6\]](https://en.wikipedia.org/wiki/Rotman_lens#cite_note-6)
1. [↑](https://en.wikipedia.org/wiki/Rotman_lens#cite_ref-1)Rotman, W\.; Turner, R\. \(November 1963\)\. "Wide\-angle microwave lens for line source applications"\.*IEEE Transactions on Antennas and Propagation*\.**11**\(6\):623–632\.[Bibcode](https://en.wikipedia.org/wiki/Bibcode_(identifier)):[1963ITAP\.\.\.11\.\.623R](https://ui.adsabs.harvard.edu/abs/1963ITAP...11..623R)\.[doi](https://en.wikipedia.org/wiki/Doi_(identifier)):[10\.1109/TAP\.1963\.1138114](https://doi.org/10.1109%2FTAP.1963.1138114)\.[ISSN](https://en.wikipedia.org/wiki/ISSN_(identifier))[0096\-1973](https://search.worldcat.org/issn/0096-1973)\.
2. [↑](https://en.wikipedia.org/wiki/Rotman_lens#cite_ref-2)[US3170158A](https://patents.google.com/patent/US3170158/en),Rotman, Walter,"Multiple beam radar antenna system",issued 1965\-02\-16[Archived](https://web.archive.org/web/20240607134817/https://patents.google.com/patent/US3170158/en)2024\-06\-07 at the[Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine)
3. [1](https://en.wikipedia.org/wiki/Rotman_lens#cite_ref-:0_3-0)[2](https://en.wikipedia.org/wiki/Rotman_lens#cite_ref-:0_3-1)["Impact of Substrate Thickness on Rotman Lens Designs \| Remcom"](https://www.remcom.com/resources/examples/impact-of-substrate-thickness-on-rotman-lens-designs)\.*www\.remcom\.com*\.[Archived](https://web.archive.org/web/20240608093809/https://www.remcom.com/resources/examples/impact-of-substrate-thickness-on-rotman-lens-designs)from the original on 2024\-06\-08\. Retrieved2024\-06\-08\.
4. [↑](https://en.wikipedia.org/wiki/Rotman_lens#cite_ref-4)["Rotman Lens"](https://www.microwaves101.com/encyclopedias/rotman-lens)\.*Microwaves101*\.[Archived](https://web.archive.org/web/20240607134818/https://www.microwaves101.com/encyclopedias/rotman-lens)from the original on 2024\-06\-07\. Retrieved2024\-06\-07\.
5. [↑](https://en.wikipedia.org/wiki/Rotman_lens#cite_ref-5)Kilic, Ozlem; Weiss, Steven J\. \(June 2010\)\.["Rotman lens applications for the US Army: A review of history, present, and future"](https://ieeexplore.ieee.org/document/7909283)\.*URSI Radio Science Bulletin*\.**2010**\(332\):10–23–via IEEE Explore\.
6. [↑](https://en.wikipedia.org/wiki/Rotman_lens#cite_ref-6)["Rotman Lens \- Radartutorial"](https://www.radartutorial.eu/06.antennas/an75.en.html)\.*www\.radartutorial\.eu*\.[Archived](https://web.archive.org/web/20240607134819/https://www.radartutorial.eu/06.antennas/an75.en.html)from the original on 2024\-06\-07\. Retrieved2024\-06\-07\.