find_lsqr_solution.m File Reference

Computes least-squares dipole excitations to reduce sidelobes in a dish antenna radiation pattern. More...

Functions
function	find_lsqr_solution (in dish_analyzer, in EdB, in Etheta, in Ephi, in theta_range, in phi, in N, in rho_loc, in phi_locs, in freq)

Detailed Description

Computes least-squares dipole excitations to reduce sidelobes in a dish antenna radiation pattern.

This function takes an existing radiation pattern and attempts to modify it by superimposing the fields from a ring of dipoles. The dipole currents are determined by solving a linear system via LSQR to match a target pattern (typically zero field) outside the main lobe.

Parameters

dish_analyzer	DishAnalyzer object containing dish geometry and analysis tools.
EdB	Normalized far-field magnitude in dB (for display/analysis only).
Etheta	Complex far-field E-theta component from the dish.
Ephi	Complex far-field E-phi component from the dish.
theta_range	1D array of theta angles at which far-fields are sampled.
phi	The azimuthal plane (fixed phi) in which the dipole pattern is optimized.
N	Number of dipoles to place around the ring.
rho_loc	Radial distance of dipoles from the dish center.
phi_locs	Array of azimuthal angles specifying dipole positions.
freq	Operating frequency [Hz].

Return values

a_vec	The complex excitation vector (current amplitudes and phases) for each dipole.
dipoles	A cell array of SimpleDipole objects used in the solution.
rectwin	A rectangular window applied over the main lobe region for field preservation.

The main lobe region is automatically detected via get_beam_width. Outside this region, the goal is to reduce the radiated field using a linear superposition of dipole patterns. The function builds a system matrix Zmn where each column is the field contribution from a dipole, and solves Zmn * a = d using LSQR.

Note

This function assumes dipoles are uniformly oriented in azimuth (tangential direction).

See also

SimpleDipole

DishAnalyzer

lsqr

Function Documentation

find_lsqr_solution()

function find_lsqr_solution	(	in	dish_analyzer,
		in	EdB,
		in	Etheta,
		in	Ephi,
		in	theta_range,
		in	phi,
		in	N,
		in	rho_loc,
		in	phi_locs,
		in	freq )