Aug 30, 2014 #1 K kuhnny Newbie level 6 Joined Sep 13, 2010 Messages 14 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,281 Activity points 1,339 Hi, I'm finding difficulty in designing unbalanced Archimedean Spiral antenna in HFSS....I designed for 1 - 10 Ghz... but it is working at one frequency 1Ghz( i.e. poor return loss at other frequencies) Behaving like narrow band antenna. I excited with lumped port between two arms. What will be the problem ? Last edited: Aug 30, 2014
Hi, I'm finding difficulty in designing unbalanced Archimedean Spiral antenna in HFSS....I designed for 1 - 10 Ghz... but it is working at one frequency 1Ghz( i.e. poor return loss at other frequencies) Behaving like narrow band antenna. I excited with lumped port between two arms. What will be the problem ?
Sep 4, 2014 #2 M maxwellian Full Member level 2 Joined Feb 22, 2005 Messages 144 Helped 26 Reputation 52 Reaction score 9 Trophy points 1,298 Activity points 3,165 What impedance did you use for your lumped port? A complementary Archimedean Spiral should exhibit an input impedance of 188 ohms.
What impedance did you use for your lumped port? A complementary Archimedean Spiral should exhibit an input impedance of 188 ohms.
Sep 4, 2014 #3 D.A.(Tony)Stewart Advanced Member level 7 Joined Sep 26, 2007 Messages 9,016 Helped 1,824 Reputation 3,647 Reaction score 2,202 Trophy points 1,413 Location Richmond Hill, ON, Canada Activity points 59,603 Did try exciting between centre and Gnd plane? Where is your design?. What dielectric properties?
Sep 4, 2014 #4 K kuhnny Newbie level 6 Joined Sep 13, 2010 Messages 14 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,281 Activity points 1,339 I used 188.5 ohms. and im getting BW of 700MHz only. but it should be around 8-10 GHz.
Sep 4, 2014 #5 M maxwellian Full Member level 2 Joined Feb 22, 2005 Messages 144 Helped 26 Reputation 52 Reaction score 9 Trophy points 1,298 Activity points 3,165 What do you mean by unbalanced? Are you using an unbalanced feed, or is there some aspect of the design that causes this to be a non-complementary antenna design? Can you post a picture of the layout?
What do you mean by unbalanced? Are you using an unbalanced feed, or is there some aspect of the design that causes this to be a non-complementary antenna design? Can you post a picture of the layout?
Sep 6, 2014 #6 K kuhnny Newbie level 6 Joined Sep 13, 2010 Messages 14 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,281 Activity points 1,339 yah. It was unbalanced feed only. Substrate is kept hidden in the image. Last edited: Sep 6, 2014