How to Build Your Own Planar Disk Antenna

Updated on January 8, 2018
tamarawilhite profile image

Tamara Wilhite is a technical writer, industrial engineer, mother of 2, and a published sci-fi and horror author.

What Is a Planar Disk Antenna?

A planar disk antenna is made from two disks stacked one above the other, close to each other without touching. Coax is soldered at the gap between the two disks/antennas. The lowest frequencies they can receive are based on the size of the disks. The gap between the disks acts like the exponential slot of a Vivaldi antenna at high frequencies. The wide frequency range that planar disk antennas can receive makes them a common type of ultra-wide band antenna.

Planar disk antennas are more sensitive to long distance signals than sources close by, making them ideal for receiving a wide range of signals like multiple ham radio bands.

A manufactured planar disk antenna by WA5VJB that the home made antenna is intended to imitate.
A manufactured planar disk antenna by WA5VJB that the home made antenna is intended to imitate.

How to Build Your Own Planar Disk Antenna

How can you build your own planar disk antenna? Pizza plates are one low cost solution.

Two pizza plates can be used to make a broad banded vertical antenna, a type of ultra-wideband antenna. Ultra wide band antennas are notable for being able to work on a frequency span of 10:1 or more. A planar disk UWB antenna could handle 1 MHz to 10 MHz signals if not a wider range, for example.

How do you make your own planar disk antennas out of pizza plates? Buy two pizza pans that are 16” to 18” across. If you use smaller 14” plates, the SWR is high for the 2 meter frequency band. 12” pans are so small they work on the broadcast FM frequencies. Steel pizza plates work better than aluminum ones.

The antennas will be mounted flat against a rod or support, one above the other with a 1/8” to ¼” gap between them. You can put construction adhesive or other non-conductive glue in this gap to help make sure they don’t touch.

You can attach the antennas to a wooden rod by screwing them in place with solder lugs; the objective is to screw them into a plank long enough to hold both without them touching. Or you can solder a steel pizza place directly to a coaxial connection. Note – aluminum coax shield won’t solder to stainless steel. If you’re having problems soldering the copper core to the plates, you can scratch the surface to help it stick.

The central conductor goes to the top pizza plate. The shield will be mounted to the lower pizza place. If this antenna is going to be used outside, silicone sealant or putty needs to be put on the feed-point. Use the same materials to seal the open coax braid.

You can spray paint the antennas with non-metallic spray paint to offer some protection from rust.

Then you can hang the antennas by hanging the mount from a cord or tying it to a support so it points the direction you want.

A group of ultra wide band antennas
A group of ultra wide band antennas | Source

Results

If you use 18” steel pizza pans, at a roughly -10 dB return loss, it will have a 2:1 SWR, and a -20 dB loss results in a 1.2:1 SWR. This means the SWR is 2:1 or better for frequencies from the 2 meter ham band (144-148 MHz) to 2 GHz frequency range.

Given these numbers, this homemade ham antenna can be used with multiband amateur radio rigs or a scanner.

References

My thanks to Kent Britain, WA5VJB, for his advice regarding for this article. He is also the designer of the antennas shown here.

Questions & Answers

    Comments

    Submit a Comment

    No comments yet.

    working

    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, turbofuture.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: https://turbofuture.com/privacy-policy#gdpr

    Show Details
    Necessary
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
    Features
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Marketing
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Statistics
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)