Electromagnetic Simulation Software

Indoor Connected Home Remote Camera
Performance Analysis with XFdtd
Introduction
The connected home concept includes many “smart” aspects including speakers,
thermostats, doorbells, and cameras. This example discusses the performance, as
simulated by XFdtd EM Simulation Software, of a generic remote camera that provides
video surveillance around the house for security monitoring. The camera is intended toconnect to a WiFi system that covers the 802.11 a/b/g/n/ac/ax standards at frequenciesof 2.4, 5, and 6 GHz and includes two multiband conformal antennas that transmit thehigh-resolution video.
Device Design and Simulation
The generic camera design uses two conformal multiband antennas that wrap aroundthe interior surface of the camera housing. The antennas are designed to provide
coverage at 2.4, 5, and 6 GHz and can be phased to steer the antenna patterns for
maximum coverage. In addition to the antennas, there are mounting structures, PCB
boards, camera imaging chips and the lens, which are represented by block parts in thissimple model. A three-dimensional CAD view of the camera is shown in Figure 1, where
one of the antenna elements is visible through the translucent case of the camera. The
entire camera fills a space of about 70x70x70 mm. In Figure 2, a more detailed viewof one of the antenna elements shows the curvature of the element to conform to theinterior wall of the camera case. The antenna has been tuned to provide reasonable
return loss of less than -10 dB at the desired frequencies of 2.4, 5, and 6 GHz as
shown in Figure 3. The curving of the antenna to fit into the case has a significant
impact on the performance of the antenna and makes tuning of the antenna in its final
configuration a necessity.

Figure 1: A three-dimensional view of a genericremote camera device is shown with the internalantenna arrays partially visible through the cover.

Figure 2: One of the two identical multiband
antennas in the remote camera.

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Indoor Connected Home Remote Camera Performance Analysis with XFdtd

Figure 3: The return loss for the multiband antenna shows good performanceat 2.4, 5 and 6 GHz as desired.

The gain patterns of the antennas have coverage focused to the sides and forward ofthe camera. The patterns of the two antennas operating independently are shown at
2.4 GHz in Figure 4, at 5 GHz in Figure 5, and at 6 GHz in Figure 6, where the front of
the camera with the lens is facing the viewer in all of the images. The peak gain of theindividual elements ranges from about 3 dBi at 2.4 GHz to nearly 7 dBi at 5 GHz. At
2.4 GHz the pattern is quite broad, while at the higher frequencies the pattern is more
complex with some lobes.

Figure 4: The gain patterns of the two antennas at 2.4
GHz show two broad lobe patterns covering half of thedevice. The orientation of the image is looking directlyat the front of the camera.

Figure 5: The gain patterns of the two antennas at 5
GHz show two narrower patterns with high gain normal
to the antenna. The orientation of the image is looking
directly at the front of the camera.

315 S. Allen St., Suite 416 | State College, PA 16801 USA | +1.814.861.1299 phone |+1.814.861.1308 fax | sales@remcom.com | www.remcom.com

Indoor Connected Home Remote Camera Performance Analysis with XFdtd

Figure 6: The gain patterns from the two antennas at 6 GHz show
multi-lobed patterns which cover most of the azimuthal plane of thedevice and have a lobe pointed in the forward direction of the camera.
The orientation of the image is looking directly at the front of the camera.

Since the camera could be mounted in a random orientation, it is desirable to havecoverage over the full range of angles. However, as there are some internal parts in thegeneric camera such as the PCB boards and support structures, the gain to the rear of
the camera is reduced. Using the array optimization features in XFdtd, the performanceof the arrays can be determined to find the full coverage possible. In Figure 7 the Max
Hold pattern is computed for the two antennas at 2.4 GHz, which shows good gain in theforward direction and around the azimuthal plane. In Figure 8, the Max Hold pattern at
5 GHz shows strong lobes to the sides of the antenna and reduced, but positive, gain in
the forward direction. At 6 GHz, shown in Figure 9, the Max Hold pattern shows strong
gain in the forward direction and lower gain to the sides. Figures 7, 8, and 9 show thepatterns with the camera oriented as shown in Figure 1.

Figure 7: The Maximum EIRP pattern of the twoantennas at 2.4 GHz shows broad coverage overthe forward region of the camera. The orientation ofthe camera in the image is identical to that shown inFigure 1.

Figure 8: The Maximum EIRP pattern of the twoantennas at 5 GHz shows high gain coverage normal
to the antenna plane in the azimuthal direction. The
orientation of the camera in the image is identical tothat shown in Figure 1.

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Indoor Connected Home Remote Camera Performance Analysis with XFdtd

Figure 9: The Maximum EIRP pattern of the two antennas at 6 GHz shows astrong gain in the forward direction and nearly even coverage in the azimuthal
direction. The orientation of the camera in the image is identical to that shownin Figure 1.

By creating a cumulative distribution function of the EIRP, it is possible to compute themaximum coverage over the full three-dimensional sphere surrounding the device. InFigure 10, the CDF of EIRP plot shows that for all possible phasing relationships ofthe elements at 2.4 GHz, positive gain is possible for about 67% of the directions. At 5GHz, the CDF plot shown in Figure 11 has just over 60% coverage with positive gain.
Finally, at 6 GHz, Figure 12 shows nearly 70% of the directions may have positive gain.

Figure 10: The CDF of EIRP plot for the two antennas
at 2.4 GHz shows positive gain for about 67% of thedirections.

Figure 11: The CDF of EIRP plot for the two antennas
at 5 GHz shows positive gain for about 60% of thedirections.

315 S. Allen St., Suite 416 | State College, PA 16801 USA | +1.814.861.1299 phone |+1.814.861.1308 fax | sales@remcom.com | www.remcom.com

Indoor Connected Home Remote Camera Performance Analysis with XFdtd

Figure 12: The CDF of EIRP plot for the two antennas at 6 GHz shows
positive gain for about 70% of the directions.

Conclusion
Maintaining good contact with a remote device such as a camera is a critical featureof any connected home system. This generic camera design has been evaluatedwith XFdtd and found to have at least positive gain for over 60% of directions at threefrequencies with peak gain as high as nearly 7 dBi. This should provide adequate
connectivity for most installation configurations.
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State College, PA 16801 USA+1.888.7 . REMCOM (US/CAN)+1.814 .861.1299 phone+1.814 .861.1308 fax© 20212019 Remcom Inc.
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315 S. Allen St., Suite 416 | State College, PA 16801 USA | +1.814.861.1299
phone | +1.814.861.1308 fax | sales@remcom.com | www.remcom.com
sales@remcom.com