HELP design dual band whip antenna

hi all
first excuse for my English

i have a project design a dual band whip antenna works at frequency 140 MHz and 440 MHz. i have simulate both of antenna in single band using HFSS. but i have problem how to make a dual band. antenna models that i would like to make is like the following image..

i need to design coil that connect both antenna and simulate it using HFSS. another whip antenna design might help me. thanks

hi i think u can made it by flooded and parasitic element around it

i need to simulate it first to calculate length of antenna. i need to determine the size of the antenna and coil first.

maybe you have any reference or books about design this kind of antenna? i will help me to learn about design this antenna.
thanks

hi
for more information about HF, VHF,and UHF antenna u can read these books :
1-antenna toolkit by joe carr
2-practical antenna handbook joe carr

---------- Post added at 12:16 ---------- Previous post was at 12:09 ----------

hi it may be useful
Whip Antenna Design Calculator
Whip Antenna Calculator

hi ferdows,
i've read books you give but still i can't find theoritical about design the coil for dual band. does it has a calculation or we can make it by our own way and not depend with any requirement such as diameter coil and how much turn we give?
and also the site you provide, i think the L (tuning inductance) calculation is used to make a loading coil not to make a coil for separated one antenna to the other one.

hi
i think u can model the antenna with equal circuit and u can find resonance and find L too

dear,
i have create my dual band design using HFSS v12.1. i've stuck because my design give a bad result. i think i've created a wrong design. please evaluate my design.
thanks all.

Reference: W. Barthomomew, Dual-Band Mobile Whip for 146/432 MHz, ARRL Antenna Compendium Vol. 5, 1996, p. 54

---------- Post added at 13:02 ---------- Previous post was at 13:00 ----------

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