mequitnever
Junior Member level 1
Hello,
I am trying to learn HFSS 12. I used the simple dipole design to start with. I am not getting the characteristic or input impedance of this simple flat dipole. Any help will be widely appreciated.
Dipole dimension:
Length = 63.05 mm because I want it to resonate at 2.26 Ghz, so taking length of the dipole to be 0.475 times the wavelength in free space.
So each arm of the dipole is 31.525 mm long. A 0.125mm gap between the arms for the lump port set to 50 ohm.
width of the dipole = 2.522 mm because the book says to approximate a circular dipole (wire) to a flat dipole use the equation:
length/diameter = 50 and diameter = 0.25*width
Dipole is in vacuum and a lump port of 50 ohm between the dipole arms.
Assuming all these, theoretically the input impedance should be 73 ohm.
While simulating in HFSS 12, I am not getting any input or characteristic impedance of the dipole antenna.
My idea of getting the input impedance is to draw the Z parameter and see where the imaginary curve crosses the zero line. But in simulation the imaginary curve never crosses zero line and it remains negative which means it is capacitive (while theoretically the imaginary part should be inductive or positive).
I have attached the simulation file.
Same problem when I put dipole on a dielectric of 1.17 mm thick TLY-5 substrate of relative permittivity 2.2. I know that for the dielectric I have to consider the effective wavelength which comes out to be 62.3 mm but my problem with the characteristic impedance remains the same - the imaginary curve of the Z parameter NEVER crosses zero line.
Please provide help. Any other method to find characteristic impedance? Any help will be highly appreciated.
I am trying to learn HFSS 12. I used the simple dipole design to start with. I am not getting the characteristic or input impedance of this simple flat dipole. Any help will be widely appreciated.
Dipole dimension:
Length = 63.05 mm because I want it to resonate at 2.26 Ghz, so taking length of the dipole to be 0.475 times the wavelength in free space.
So each arm of the dipole is 31.525 mm long. A 0.125mm gap between the arms for the lump port set to 50 ohm.
width of the dipole = 2.522 mm because the book says to approximate a circular dipole (wire) to a flat dipole use the equation:
length/diameter = 50 and diameter = 0.25*width
Dipole is in vacuum and a lump port of 50 ohm between the dipole arms.
Assuming all these, theoretically the input impedance should be 73 ohm.
While simulating in HFSS 12, I am not getting any input or characteristic impedance of the dipole antenna.
My idea of getting the input impedance is to draw the Z parameter and see where the imaginary curve crosses the zero line. But in simulation the imaginary curve never crosses zero line and it remains negative which means it is capacitive (while theoretically the imaginary part should be inductive or positive).
I have attached the simulation file.
Same problem when I put dipole on a dielectric of 1.17 mm thick TLY-5 substrate of relative permittivity 2.2. I know that for the dielectric I have to consider the effective wavelength which comes out to be 62.3 mm but my problem with the characteristic impedance remains the same - the imaginary curve of the Z parameter NEVER crosses zero line.
Please provide help. Any other method to find characteristic impedance? Any help will be highly appreciated.