Radar Receiver

You can model the following components of a radar receiver:

Specs

You can specify the following parameters:

Parameter Description
Antenna to LNA Line Loss Enter the value for the loss of the transmission line between the antenna and the Low Noise Amplifier.
LNA Gain Enter tha value for the gain introduced by the LNA.
LNA to Receiver Line Loss Enter the value for the loss of the transmission line between the LNA and the Receiver.
Rain Model

Select the Use check box to use the rain model in your scenario; you must select a global Rain Model on the scenario's RF Environment properties page. Enter the value of Outage Percent to set the maximum percent outage for the rain model. To disable the Rain Model used in the calculation for this receiver, clear the Use check box. For rain model descriptions, see Rain Model.

If the Rain Model is not selected at the scenario level, the rain model parameters are unavailable.

RF Filter

You can enable power spectral density (PSD) analysis and RF spectrum filters on the radar object.

Radar objects use signal power spectral density analysis to compute the reflected signal power as seen by the radar receivers front-end bandwidth.

The fidelity of the radar system analysis is enhanced by taking into account the signal spectrum and the distribution of power across the frequency band.

The receive side filter updates the spectrum shape of the incoming radar return signal. The filters can be used to enhance the spectral components or to suppress the unwanted jamming signal.

Starting with STK 10.1, the RF filter on the radar receive side is placed in front of the Low Noise Amplifier (LNA). This will impact all incoming signals across the bandwidth of the receive RF filter.

Enter a value for the LNA Bandwidth, which is the default value for the radar-receiver Low Noise Amplifier (LNA) bandwidth. This value is used to compute the received signal power across the radar receiver bandwidth. A uniform characteristic response model is used across the LNA bandwidth.

The use of a receive-side RF filter determines the radar receiver bandwidth. The receiver RF filter characteristics are used to compute the received signal power. In this case, the receiver RF filter bandwidth will (internally) override the LNA bandwidth value.

When RF filters are used, their respective bandwidths are used to determine the transmitter signal and receiver bandwidths. STK retains the specified LNA bandwidth GUI value for later use.

Filter Model. To specify a filter model, select the Use check box. The click the elipsis button to browse to and select a filter model. For more information, see Filter Models.

Polarization

To specify a polarization model, select the Use check box. In the drop-down menu, select a polarization type. For descriptions of the polarization types and parameters, see Polarization. Also, select the Enable Orthogonal Polarization check box if you desire this effect.

System Noise Temperature

You can set noise temperature by selecting Constant and entering a value directly. Or, you can have STK calculate the system temperature for you. To do so, select Compute and specify the parameters that STK will use in calculating noise temperature. For parameter descriptions, see System Noise Temperature.

Sensitivity Time Control Attenuation (STC)

To specify STC attenuation parameters, select the Enable Rf STC or Enable If STC (or both) check boxes. Use the drop-down menu to select an STC attenuation type. For descriptions of the STC attenuation types and parameters, see Radar Sensitivity Time Control (STC).

Additional Gains and Losses

For Pre-Receive Gains/Losses, you can introduce a gain or loss by clicking Add. Enter a brief description of the gain or loss in the Identifier field and enter its value in the Gain field. Remember to make it negative if you are entering a loss. After entering the values, you can click Remove to delete an entry from the table or click Remove All to delete all the entries. To modify an existing entry, simply edit the fields in the grid. The value in the Total Gains/Losses field will reflect the net value of all gains and losses recorded in the table.

For more information on modeling gains and losses that affect performance but are not defined using built-in analytical models, see Pre-Receive and Pre-Demod Gains & Losses.