txsite

Create RF transmitter site

Description

Use a txsite object to create a radio frequency transmitter site.

A transmitter consists of an RF circuit and an antenna, where the RF circuit excites the antenna with a signal and power. Key characteristics of a transmitter include its output power, operating frequency, and antenna radiation pattern.

Creation

Syntax

tx = txsite

tx = txsite(coordsys)

tx = txsite(___,Name=Value)

Description

tx = txsite creates a radio frequency transmitter site in geographic coordinates.

tx = txsite(coordsys) sets the CoordinateSystem property. By default, transmitter sites use a geographic coordinate system. Create a transmitter site that uses a Cartesian coordinate system by specifying coordsys as "cartesian".

tx = txsite(___,Name=Value) sets properties using one or more name-value arguments.

• For geographic transmitter sites, you can specify the location by setting the Latitude, Longitude, and AntennaHeight properties.

• For Cartesian transmitter sites, you can specify the location by setting the AntennaPosition property.

Properties

Name — Site name

character vector | string scalar | row or column vector

Site name, specified as a character vector, a string scalar, or a row or column vector of N elements, where N is the number of sites. Create multiple sites by specifying a row or column vector.

Example: tx.Name = "Fenway Park";

Example: tx.Name = ["Fenway Park","Faneuil Hall","Bunker Hill Monument"];

Data Types: char | string

CoordinateSystem — Coordinate system used to reference site location

'geographic' (default) | 'cartesian'

Coordinate system used to the reference the location of the site, specified as 'geographic' or 'cartesian'.

• 'geographic' — Geographic coordinate system. Specify the locations of the transmitter sites using the Latitude, Longitude, and AntennaHeight properties.

• 'cartesian' — Cartesian coordinate system. Specify the locations of the transmitter sites using the AntennaPosition property.

Example: tx.CoordinateSystem = "cartesian"

Latitude — Latitude coordinates of site, in degrees

42.3001 (default) | numeric scalar in the range [–90, 90] | row or column vector

Latitude coordinates of the site, in degrees, specified as a numeric scalar in the range [–90, 90], or as a row or column vector of N elements in the range [–90, 90]. Create multiple sites by specifying a row or column vector.

The coordinates are referenced using the World Geodetic System of 1984 (WGS 84) reference ellipsoid.

Example: tx.Latitude = 45.098

Example: tx.Latitude = [42.3467 42.3598 42.3763];

Dependencies

To enable this property, the value of CoordinateSystem must be 'geographic'.

Longitude — Longitude coordinates of site, in degrees

-71.3504 (default) | numeric scalar in the range [–180, 180] | row or column vector

Longitude coordinates of the site, in degrees, specified as a numeric scalar in the range [–180, 180], or as a row or column vector of N elements in the range [–180, 180]. Create multiple sites by specifying a row or column vector.

The coordinates are referenced using the WGS 84 reference ellipsoid.

Example: tx.Longitude = -71.0972

Example: tx.Longitude = [-71.0972 -71.0545 -71.0611];

Dependencies

To enable this property, the value of CoordinateSystem must be 'geographic'.

Antenna — Antenna element or array

'isotropic' (default) | antenna element | array element | row vector

Antenna element or array, specified as one of these options:

• 'isotropic', which models an antenna that radiates uniformly in all directions.

• An antenna element from the Antenna Catalog (Antenna Toolbox) or an array element from the Array Catalog (Antenna Toolbox). To specify an antenna element, design the antenna element at the required receive frequency by using the design (Antenna Toolbox) function. Then, add the antenna element to the transmitter site. This option requires Antenna Toolbox™.

• An arrayConfig object. This option requires Communications Toolbox™.

• An antenna object in Antennas, Microphones, and Sonar Transducers (Phased Array System Toolbox) or an array object in Array Geometries and Analysis (Phased Array System Toolbox). This option requires Phased Array System Toolbox™.

Example: tx.Antenna = arrayConfig('Size',[8 1]); specifies an 8-element ULA along the z-axis

AntennaAngle — Antenna x-axis angle, in degrees

0 (default) | numeric scalar | 2-by-1 vector | 2-by-N matrix

Antenna x-axis angle defined with reference to a local Cartesian coordinate system, in degrees, specified as a numeric scalar representing an azimuth angle or as a 2-by-1 vector or a 2-by-N matrix representing both azimuth and elevation angles.

For sites with geographic coordinates, the azimuth angle is measured counterclockwise from the east along the antenna x-axis. For sites with Cartesian coordinates, the azimuth angle is measured from the global x-axis around the global z-axis. Specify the azimuth angle in the range [–180, 180].

The elevation angle is measured from the antenna x-axis along the horizontal (or xy) plane. Specify the elevation angle in the range [–90, 90].

Example: tx.AntennaAngle = 25;

Example: tx.AntennaAngle = [25 -80];

AntennaHeight — Antenna height above surface, in meters

10 (default) | nonnegative numeric scalar | row vector

Antenna height above the ground or building surface, in meters, specified as a nonnegative numeric scalar. This value must be less than or equal to 6,371,000 m.

If the site location coincides with the building location, the antenna height is measured from the top of the building to the center of the antenna. Otherwise,the height is measured from ground elevation to the center of the antenna.

Example: tx.AntennaHeight = 15;

Dependencies

To enable this property, the value of CoordinateSystem must be 'geographic'.

Data Types:

AntennaPosition — Position of antenna center, in meters

[0;0;0] (default) | 3-by-1 vector

Position of the antenna center, in meters, specified as a 3-by-1 vector representing x-, y-, and z-axis Cartesian coordinates.

Example: tx.AntennaPosition = [0;2;4];

Dependencies

To enable this property, the value of CoordinateSystem must be 'cartesian'.

Data Types:

SystemLoss — System loss in dB

0 (default) | nonnegative scalar | row vector

System loss in dB, specified as a nonnegative scalar.

System loss includes transmission line loss and any other miscellaneous system losses.

Example: tx.SystemLoss = 10;

Data Types:

TransmitterFrequency — Transmitter operating frequency, in Hz

1.9000e+09 (default) | positive scalar | row vector

Transmitter operating frequency, in Hz, specified as a positive scalar or a row vector. When you specify a row vector, the number of elements in the row vector must match the number of sites.

When the Antenna property contains an antenna element from the Antenna Catalog (Antenna Toolbox) or an array element from the Array Catalog (Antenna Toolbox), the frequency must be in the range [1e3, 200e9].

When you use the transmitter site in a propagation analysis, the frequency must be within the frequency range for the propagation model. For more information about the valid frequency ranges for different propagation models, see Choose a Propagation Model.

Example: tx.TransmitterFrequency = 30e9;

Data Types: double

TransmitterPower — Signal power at transmitter output, in W

10 (default) | positive scalar

Signal power at transmitter output, in W, specified as a positive scalar. The transmitter out is connected to the antenna. When Antenna specifies an antenna array, this property specifies the total signal power to the array.

Example: tx.TransmitterPower = 30;

Data Types: double

Object Functions

show	Show site in Site Viewer
hide	Hide site from Site Viewer
distance	Distance between sites
angle	Angle between sites
elevation	Elevation of site
location	Coordinates at distance and angle from site
los	Display or compute line-of-sight (LOS) visibility status
coverage	Display or compute coverage map
sinr	Display or compute signal-to-interference-plus-noise (SINR) ratio
pattern	Display antenna radiation pattern in Site Viewer

Examples

Create Transmitter Site in Geographic Coordinates

Create a transmitter site. By default, transmitter sites use geographic coordinates. Specify the latitude as 42.3001 degrees and the longitude as -71.3504 degrees.

tx = txsite(Name="MathWorks Apple Hill", ...
    Latitude=42.3001,Longitude=-71.3504);

Display the antenna radiation pattern for the site.

pattern(tx)

Create Transmitter Site Using Dipole Antenna

Create a dipole antenna that has a resonant frequency of 2.5e9 Hz. Create a transmitter site in geographic coordinates that uses the dipole antenna.

fq = 2.5e9;
ant = design(dipole,fq);

tx = txsite(Name="MathWorks Apple Hill", ...
    Latitude=42.3001,Longitude=-71.3504, ...
    Antenna=ant,TransmitterFrequency=fq);

Display the transmitter site.

show(tx)

Create Transmitter Array Using Dipole Antennas

Specify the names, latitudes, and longitudes of three locations.

name = ["Fenway Park","Faneuil Hall","Bunker Hill Monument"];
lat = [42.3467 42.3598 42.3763];
lon = [-71.0972 -71.0545 -71.0611];

Specify the frequency of the transmitters in Hz.

fq = 2.5e9;

Create an array of transmitter sites in geographic coordinates that uses dipole antennas.

txs = txsite(Name=name,Latitude=lat,Longitude=lon, ...
Antenna=dipole,TransmitterFrequency=fq);

Display the transmitter sites.

show(txs)

Version History

Introduced in R2019b