From abe447a8cd776537bea5c33eb825025b8b3cbdf0 Mon Sep 17 00:00:00 2001 From: Craig Warren Date: Thu, 14 Jan 2016 16:20:42 +0000 Subject: [PATCH] Updated l/lambda to 0.475. --- docs/source/examples_antennas.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/docs/source/examples_antennas.rst b/docs/source/examples_antennas.rst index 4c938388..0575770c 100644 --- a/docs/source/examples_antennas.rst +++ b/docs/source/examples_antennas.rst @@ -45,7 +45,7 @@ Results Detailed view of input admittance and impedance (resistance and reactance) and s11 parameter values of the antenna (:math:`\Delta f = 17~MHz`). -:numref:`antenna_wire_dipole_fs_tl_params` shows time histories and frequency spectra of the incident and total (incident + reflected) voltages and currents in the transmission line. :numref:`antenna_wire_dipole_fs_ant_params` shows the input admittance and impedance (resistance and reactance), and s11 parameter of the half-wavelength wire dipole. :numref:`antenna_wire_dipole_fs_ant_params_detail` shows a more detailed view of these parameters. The s11 parameter shows that the first resonance of the antenna is at 950MHz. Depending on the radius of the wire, the length of the dipole for first resonance is about :math:`l=0.47\lambda` to :math:`0.48\lambda`. The thinner the wire the closer the resonance is to :math:`0.48\lambda` [BAL2005]_. In this case, with a first resonance of 950MHz and a length of 150mm, :math:`l/\lambda=0.47`. The input impedance is :math:`Z_{in} = 71 - j16~\Omega`. If :math:`l/\lambda=0.5` then the theoretical input impedance would be :math:`Z_{in} = 73 + j42.5~\Omega`. The reactive (imaginery) part associated with the input impedance of a dipole is a function of its length. +:numref:`antenna_wire_dipole_fs_tl_params` shows time histories and frequency spectra of the incident and total (incident + reflected) voltages and currents in the transmission line. :numref:`antenna_wire_dipole_fs_ant_params` shows the input admittance and impedance (resistance and reactance), and s11 parameter of the half-wavelength wire dipole. :numref:`antenna_wire_dipole_fs_ant_params_detail` shows a more detailed view of these parameters. The s11 parameter shows that the first resonance of the antenna is at 950MHz. Depending on the radius of the wire, the length of the dipole for first resonance is about :math:`l=0.47\lambda` to :math:`0.48\lambda`. The thinner the wire the closer the resonance is to :math:`0.48\lambda` [BAL2005]_. In this case, with a first resonance of 950MHz and a length of 150mm, :math:`l/\lambda=0.475`. The input impedance is :math:`Z_{in} = 71 - j16~\Omega`. If :math:`l/\lambda=0.5` then the theoretical input impedance would be :math:`Z_{in} = 73 + j42.5~\Omega`. The reactive (imaginery) part associated with the input impedance of a dipole is a function of its length. :numref:`antenna_wire_dipole_fs_ant_params_detail_1p4MHz` demonstrates the increased frequency resolution (:math:`\Delta f = 1.4~MHz`) when an even longer time window (700ns) is used.