## Antenna - Theory .com: The Antenna Site

antenna-theory.com :: View topic - Vivaldi Antenna Explanation
antenna-theory.com
Antenna Theory

Author Message
wolberine
Antenna Theory Regular

Joined: 01 Mar 2011
Posts: 35

 Posted: Tue Sep 18, 2012 2:30 pm    Post subject: Vivaldi Antenna Explanation I really enjoyed reading the Vivaldi antenna thought process and seeing how the author used intuition to design the antenna rather than equations. I believe I have a decent understanding... At 3.5GHz, the antenna is radiating similar to an IFA and at 5.5GHz, the antenna is radiating similar to a slot antenna. We taper the slot to increase antenna area, which typically increases bandwidth. We repeat the taper on the ground plane for a similar effect. At 1GHz resonance, we see better VSWR because the impedance matching is getting better with tapering. How would the curve of the taper change the characteristics? (ideas... concave vs convex curve or slower rate of change for the curve?) Also is this method how antenna structures are designed for cell phones/consumer devices with high space constraints? Or is there much more simulation involved before a mock-up? Thanks for reading!
bigSteve
Antenna Wizard

Joined: 14 Mar 2009
Posts: 265

 Posted: Wed Sep 19, 2012 1:06 am    Post subject: Vivaldi Antenna By tapering the slot, we are reducing a lot of the capacitance that exists between the two halfs of the antenna. Bandwidth generally rises with decreased capacitance. THe total volume of the antenna is essentially the same. Changing the taper speed would be a good study. It's tough to estimate, but if you taper extremely quickly you would just have the dipole mode. If you taper very slowly you would have the slot mode at the beginning of the page. As for phones, different companies rely on simulation or mockups to different degrees. It ends up being a combination of the two - and a lot of experimentation. http://www.antenna-theory.com/antennas/aperture/vivaldi.php
 Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First
 All times are GMT Page 1 of 1

 Jump to: Select a forum The Antenna Forum----------------Questions Related to Antenna TheoryNews
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum