RF Analysis
-----------

**Location:** ``TestBenches / AraTestBenches / RF / *``

There are two separate RF test benches, named **Directivity** and
**SAR**. Both provide excitation for the RF model to be tested, set up
the simulation space, then execute OpenEMS and the related
post-processing tasks. The **Directivity** testbench is focused on the
evaluation of the antenna performance (directivity, S11, ZIN, etc.) with
the FDTD simulation space reduced to the size of the Ara endo. The
**SAR** testbench, on the other hand, includes models both for an the
entire Ara endo and a head phantom, over which the SAR is calculated.

For details on using the RF analysis interpreter, refer to section
CyPhy2RF.

.. FIXME: `CyPhy2RF <@ref%20cyphy2rf>`__.

Configure
~~~~~~~~~

Create a copy of the **Directivity** or **SAR** testbench. Connect the
*Excitation* test component to the RF design under test, see the
connection leading to *InvertedFAssembly* in the figure below:

.. figure:: images/cyphy2rf-11-06-testbench.png

   Configured copy of the **RF / SAR** testbench with **InvertedFAssembly**
   as the system under test.

Metrics
~~~~~~~

+-----------------------+----------------+-----------------------------------+
| Name                  | Unit           | Description                       |
+=======================+================+===================================+
| Directivity           | dBi            | The maximum power density the     |
|                       |                | tested antenna radiates in any    |
|                       |                | direction relative to that of an  |
|                       |                | isotropic antenna.                |
+-----------------------+----------------+-----------------------------------+
| Maximum SAR           | Watts / kg     | The maximum SAR value across the  |
|                       |                | head phantom measured with        |
|                       |                | averaging over volumes that       |
|                       |                | contain 1 g tissue.               |
+-----------------------+----------------+-----------------------------------+