Application Note

VISHAY VITRAMON
Ceramic Chip Antenna
Application Note
VJ 6040 Layout Design Principles
LAYOUT DESIGN PRINCIPLES FOR VJ 6040
UHF ANTENNA
ANTENNA ENVIRONMENT
VJ 6040 is a multi-layer ceramic chip antenna designed for
receiving mobile digital TV transmissions in the UHF band.
VJ 6040, like any other antenna, will be affected by any
nearby conducting element.
The most challenging target application for the VJ 6040
antenna is the cellular phone. For this reason the following
document offers design principles that will allow best
performance of the VJ 6040 antenna, while maintaining a
form factor suitable for most cellular phone designs.
This effect can be helpful, as in the case of the ground plane.
However, it can also be harmful.
To help in the design-in process, Vishay offers an antenna
evaluation kit designed according to the principles described
hereafter. The evaluation kit allows designers to test the
antenna performance. The evaluation kit measures 40 mm
by 90 mm and includes the following:
• VJ 6040 antenna mounted against a 40 mm by 80 mm
ground plane
• Active digital tuning circuit controlled by two input lines
allowing full coverage of the UHF band 470 to 860 (MHz)
• 50 W SMA termination
Applications that allow larger ground planes can enjoy
improved antenna efficiency.
For any technical support please contact: [email protected]
General
When the application is being designed, it is crucial to
maximize the benefits offered by correct implementation of
the ground plane and minimize the potentially harmful effects
of other conduction components.
All cellular applications include at least a single antenna
designed for the cellular network itself. Because VJ 6040 is
similar to most of these antennas, the same design
considerations can be applied to both antennas. For this
reason we recommend positioning VJ 6040 close to the
cellular antenna. By doing so we can achieve the following
goals:
• Both antennas will benefit from the same ground plane
• No additional real estate will be required. Both antennas
will use the same ground clearance
• Both antennas will enjoy favorable positioning away from
the user's hand and other potentially harmful elements
such as battery, connectors, buttons etc.
• The cellular antenna can be easily customized to perform
well in the presence of VJ 6040
• VJ 6040 will not be significantly affected by the presence
of the cellular antenna, provided a minimal gap between it
and the neighboring antenna will be kept
Ground Plane Configuration
Figure 1 describes two recommended reference ground
plane configurations.
Document Number: 45129
Revision: 18-Jun-10
For technical questions, contact: [email protected]
www.vishay.com
1
APPLICATION NOTE
VJ 6040 evaluation kit demonstrates exceptional antenna
performance achieved with a 40 mm by 80 mm ground plane.
Applications that allow an increase in the overall dimensions
of the ground plane will enjoy improved efficiency.
Application Note
Vishay Vitramon
VJ 6040 Layout Design Principles
40 mm
40 mm
10 mm
15.5 mm
VISHAY
VJ 6040
50 Ω
3 mm
3 mm
10.5 mm
10.5
mm 6
mm
10.5
mm
V IS HAY
VJ 6040
50 Ω
15.5 mm
10 mm
15.5 mm
10 mm
VISHAY
VJ 6040
3
mm
RF Feed
RF Feed
50 O hm
80 mm
80 mm
Minimal ground
plane for
EMBRI
compliance
Enhanced
performance
configuration
RF Feed
Legend:
Ground plane on top, bottom and inner layers
Legend:
Ground plane on top, bottom and/or inner layers.
Copper free area on all layers
APPLICATION NOTE
VISHAY
VJ 6040
Copper free area on all layers. Discrete component
are allowed
VJ 6040 Multi-layer chip antenna
Copper and component free area on all layers
Fig. 1 - Recommended Ground Plane Configurations
Fig. 2 - Component Free Area Description
The design on the left describes the minimal area required to
allow VJ 6040 to comply with the EMBRI standard. This
configuration is used by the VJ 6040 evaluation kit. The
design on the right describes how to increase the antenna
efficiency by approximately 2 dB by enlarging the antenna
clearance. Note that antenna tuning will shift up in frequency
as antenna clearance increases. This shift should be
corrected by modifying the tuning circuit values.
The areas marked in green are less sensitive to the presence
of conducting bodies than the areas marked by the diagonal
pattern. In cases where the ground clearance must be
utilized, it is recommended positioning small discrete
components in these areas. The discrete components
should be connected using the thinnest wires possible. Large
conducting components such as batteries, connectors or
buttons should be avoided.
Applications that can support ground planes larger than
80 mm will also benefit from improved antenna parameters.
The areas closest to the antenna, marked by the diagonal
pattern, are sensitive to the presence of any conducting
body. Violating this clearance might result in antenna
detuning or loss of radiation efficiency.
For best antenna performance, it is recommended to keep
the copper free area, marked in green, free of any conducting
elements such as SMT components, connectors, batteries,
wires etc. Applications that cannot comply with this
recommendation, due to insufficient space, should follow the
guidelines presented in figure 2.
In cases where the antenna clearance is shared by both
VJ 6040 and an additional antenna, it is recommended to
maintain maximum distance between the antennas. Most
cellular antennas are mounted on a plastic carrier and are
not soldered directly to the main PCB. In these cases, the
plastic carrier can be designed to meet the recommended
clearance as described above.
Technical support for antenna integration is provided by
Vishay Vitramon division.
www.vishay.com
2
For technical questions, contact: [email protected]
Document Number: 45129
Revision: 18-Jun-10
Application Note
Vishay Vitramon
VJ 6040 Layout Design Principles
Z AXIS DESIGN PRINCIPLES
The following section deals with the recommended
clearance required by VJ 6040 in the Z axis. As in the case
of the PCB clearance, the area closest to the antenna is
sensitive to the presence of any conducting materials. The
following figure provides recommendations for the clearance
required in elevation:
10 mm
15.5 mm
Plastic housing materials, or any other non-conducting
materials, will have negligible effect on the antenna provided
that they do not physically touch it. A distance greater than
1 mm should be maintained between the plastic housing and
the antenna.
10 mm
10 mm
10 mm
Legend:
FR4 PCB
Copper and component free area on all layers
Fig. 3 - Side View of Antenna assembled on PCB
Features are subject to revisions or changes without notification
The company’s products are covered by one or more of the following:
WO2008250262 (A1), US2008303720 (A1), US2008305750 (A1), WO2008154173 (A1). Other patents pending.
ORDERING INFORMATION
VISHAY MATERIAL
PACKAGING QUANTITY
VJ 6040
VJ6040M011SXISRA0
1000 pieces
For technical questions, contact: [email protected]
www.vishay.com
3
APPLICATION NOTE
Document Number: 45129
Revision: 18-Jun-10
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