Datasheet

ANT-GNSSCP-SM12L1
Surface-Mount Ceramic Patch GNSS Antenna
The GNSSCP-SM12L1 is a 12 mm x 12 mm squaresurface-mount ceramic patch antenna for embedded
GPS/GLONASS/GALILEO/BeiDou global navigation
satellite system (GNSS) operation. It provides gain
and radiation pattern performance supporting
solutions with high location accuracy, rapid satellite
signal reception and lock, and quick time to first fix.
The GNSSCP-SM12L1 offers an extended
temperature range to +105 °C for compliance toautomotive standard AEC-Q200 Grade 2.
The GNSSCP-SM12L1 is available in tape andreel packaging and is designed for reflow-solder
mounting directly to a printed circuit board for highvolume applications.

FeaturesApplications• Performance at 1567.24 MHz to 1583.6 MHz― VSWR: ≤ 7.0― Peak Gain: 2.9 dBi― Efficiency: 53%• Directional radiation pattern orthogonal toantenna surface• Right-hand circularly polarized (RHCP)• Extended operation to +105 °C• AEC-Q200 Grade 2 compliance• Omnidirectional radiation pattern• Direct surface-mount PCB attachment• Reflow- or hand-solder assembly• Global navigation GNSS― GPS L1― Galileo E1― GLONASS II L1― Beidou B1-BOC― QZSS L1• Timing solutions• Automotive location

Ordering Information
Part Number
ANT-GNSSCP-SM12L1Description
GNSS ceramic patch antenna with surface-mount solder connection

Available from Linx Technologies and select distributors and representatives.

ANT-GNSSCP-SM12L1

Datasheet

Electrical Specifications
GNSSCP-SM12L1
Center Frequency
Frequency Range
VSWR (max)Peak Gain (dBi)
10 Deg. Elevation (dBi)
Axial Ratio (dB)
Average Gain (dBi)
Efficiency (%)
Polarization
Radiation
Max PowerWavelength
Electrical Type
Impedance
Connection
Operating Temperature Range
WeightDimensions
ESD Sensitivity

GPS L1, GALILEO E1, GLONASS IIL1, Beidou B1-BOC, QZSS L1

GLONASS II L1

1575.42 MHz
1567.24 MHz to 1583.60 MHz
7.0
2.9
2.0
19.7
-3.5
53

1602 MHz
1593.31 MHz to 1608.68 MHz
6.1
1.0
1.6
18.4
-3.4
51

RHCP
Omnidirectional
8W
1/4-wave
Ceramic Patch
50 Ω
Surface-Mount-40 °C to +105 °C
3.2 g (0.11 oz)
12.0 mm x 12.0 mm x 4.0 (0.47 in x 0.47 in x 0.16 in)
NOT ESD sensitive. As a best practice, Linx may use ESD packaging.

Electrical specifications and plots measured with a 50 mm x 50 mm (1.97 in x 1.97 in) reference ground plane.

Product Dimensions
Figure 1 provides dimensions for the GNSSCP-SM12L1 antenna.

4.0 mm(0.16 in)12.0 mm(0.47 in)

TECHNOLOGIESANT-GNSSCP-SM12L1

12.0 mm(0.47 in)

0.8 mm(0.03 in)

2.0 mm(0.08 in)

2.0 mm(0.08 in)

1.5 mm(0.06 in)Figure 1. GNSSCP-SM12L1 Antenna Dimensions
12.4724.16

Datasheet

ANT-GNSSCP-SM12L1VSWR

76040

530

4203Reflected Power (%)

506VSWR

1609

1601
1602

1593

1584

1575

81567

Figure 2 provides the voltage standing wave ratio (VSWR) across the antenna bandwidth. VSWR describes
the power reflected from the antenna back to the radio. A lower VSWR value indicates better antenna
performance at a given frequency. Reflected power is also shown on the right-side vertical axis as a gauge ofthe percentage of transmitter power reflected back from the antenna.

10211560

1570

1580
1590
Frequency (MHz)

01610

1600

Figure 2. GNSSCP-SM12L1 VSWR

Return Loss

1609

1601
1602

1593

1584

1575

01567

Return loss (Figure 3), represents the loss in power at the antenna due to reflected signals. Like VSWR, alower return loss value indicates better antenna performance at a given frequency.

-2

Return Loss (dB)

-4-6-8-10-12-14-16-18-20
1560

1570

1580
1590
Frequency (MHz)

1600

1610

Figure 3. GNSSCP-SM12L1 Return Loss

3

ANT-GNSSCP-SM12L1

Datasheet

Peak Gain

1609

1601
1602

1593

1584

1575

51567

The peak gain across the antenna bandwidth is shown in Figure 4. Peak gain represents the maximum
antenna input power concentration across 3-dimensional space, and therefore peak performance at a given
frequency, but does not consider any directionality in the gain pattern.

Peak Gain (dBi)0-5-10-15-20
1560

1570

1580
1590
Frequency (MHz)

1600

1610

Figure 4. GNSSCP-SM12L1 Peak Gain

Average Gain

1609

1601
1602

1593

1584

1575

5

1567

Average gain (Figure 5), is the average of all antenna gain in 3-dimensional space at each frequency,
providing an indication of overall performance without expressing antenna directionality.

Average Gain (dBi)0-5-10-15-20
1560

1570

1580
1590
Frequency (MHz)Figure 5. GNSSCP-SM12L1 Antenna Average Gain

41600

1610

Datasheet

ANT-GNSSCP-SM12L1

Axial Ratio

1609

1601
1602

1593

1584

1575

30

1567

Axial ratio provides a measure of the quality of circular polarization of an antenna, the lower the value (indB), the better the circular polarization. A circularly polarized antenna field comprises two orthogonal E-fieldcomponents.These fields are ideally of equal amplitude, resulting in an axial ratio equal to unity (0 dB). In
practice, no antenna is perfectly circular in polarization, the polarization is elliptical as one field has larger
magnitude. As the axial ratio increases the antenna gain degrades away from the main beam orthogonal tothe antenna surface. The axial ratio for the SM12L1 antenna is shown in Figure 6.

Axial Ratio (dB)2520
1510501560

1570

1580
1590
Frequency (MHz)

1600

1610

Figure 6. GNSSCP-SM12L1 Antenna Axial Ratio

Radiation Efficiency

1609

1601
1602

1593

1584

1575

100

1567

Radiation efficiency (Figure 7), shows the ratio of power delivered to the antenna relative to the powerradiated at the antenna, expressed as a percentage, where a higher percentage indicates better performanceat a given frequency.

9080
Efficiency (%)

7060
50
4030
201001560

1570

1580
1590
Frequency (MHz)

1600

1610

Figure 7. GNSSCP-SM12L1 Antenna Radiation Efficiency

5

ANT-GNSSCP-SM12L1

Datasheet

Radiation Patterns
Radiation patterns provide information about the directionality and 3-dimensional gain performance of theantenna by plotting gain at specific frequencies in three orthogonal planes. Antenna radiation patterns areshown in Figure 8 using polar plots covering 360 degrees. The antenna graphic at the top of the page
provides reference to the plane of the column of plots below it. Note: when viewed with typical PDF viewing
software, zooming into radiation patterns is possible to reveal fine detail.

XZ-Plane Gain

YZ-Plane Gain

XY-Plane Gain

1567.24 MHz to 1583.60 MHz (1576 MHz)
3435

33
32
31
30
29
28

36 50-5-10-15-20-25-30-35-40-45-50

123434

533
632
731
826
2530
929

1028

1127

122627212019181723434

5632
731830929102811271226

XZ-Plane Gain

2120191817123456789101225

132415221636 50-5-10-15-20-25-30-35-40-45-50

11142335

33131522124142336 50-5-10-15-20-25-30-35-40-45-50

25132435

1423

1615
2221

YZ-Plane Gain

20

191817161567 MHz
1576 MHz
1584 MHzXY-Plane Gain

1593.31 MHz to 1608.68 MHz (1601 MHz)3435333231302928

36 50-5-10-15-20-25-30-35-40-45-50

123434

533
632
731
826
25

291028

1127

1226

13
1423

15
22

21

20

1918

XZ-Plane Gain

171630927

2435

36 50-5-10-15-20-25-30-35-40-45-50

1234

34

533
632
731
825
1423

15
22

21

20

19

18

1730
929

1028

1127

1226

1324

36 5
0-5-10-15-20-25-30-35-40-45-50

123

4
5
6
78
910
11
12

25

1324

1423

16

YZ-Plane Gain

Figure 8. ANT-GNSSCP-SM12L1 Radiation Patterns

635

15222120191817XY-Plane Gain

161593 MHz
1601 MHz
1609 MHz50x50mm

Datasheet

ANT-GNSSCP-SM12L1

Ground Plane
Ceramic patch antennas are directional in signal transmission and reception orthogonal to the surface plane
ANT-GNSSCP-SM12L1of the antenna, and require a ground plane for proper operation. Thelarger the ground plane, the narrower
the antenna signal beam, and generally, the better the VSWR performance of the antenna. Relatively smaller
ground planes produce wider signal beams. Linx recommends the ground plane size shown in the Electrical
Specifications table to achieve performance similar to that shown in this datasheet. Other ground plane sizes
and antenna mounting locations are possible. The antenna should be mounted at the center of the groundplane for best performance. Linx offers PCB design reviews to help optimize solution performance.

Recommended Layout
The recommended printed circuit board (PCB) layout for the SM12L1 antenna is demonstrated by the Linx
AEK-GNSSCP-SM12L1 evaluation board shown in Figure 9. Contact LinxAEK-GNSSCP-SM12L1
for availability of PCB layout
www.linxtechnologies.com
design files.
Copyright © 2020 Linx Technologies
The recommended layout includes a matching network, ground plane and PCB transmission line fromthe antenna to the matching network, and to the connector or radio circuitry. The connector used for theevaluation board is optional, the transmission line may be run directly to the radio if on the same PCB.
Linx recommends inclusion of at least a 3-element, surface mount pi matching network of two parallel
capacitors, (C1, C2) and one serial inductor, (L1) in all designs (Figure 10). Surface mount components
should be 0603 size. 0402 size components are also supported. The GNSSCP series antennas, asdesigned, do not require matching, but matching may improve end-product antenna performance dependingon the effects of the enclosure, PCB and other electronic components. If no matching is necessary, the serial
element may be populated with a zero-ohm resistor and no component in the two capacitor positions. This is
the configuration of the Linx evaluation board as supplied. Linx believes in wireless made simple® and offers
matching network design support.
SM12L1 antenna
50x50mm

PCB pads for the SM12L1 antenna

Ground Plane Area =50 mm x 50 mm(1.97 in x 1.97 in)

Ground plane on bottom layer forcounterpoise

ANT-GNSSCP-SM12L1

Pi matching circuit

C1C2

TECHNOLOGIES

L1

ANT-GNSSCP-SM12L1

SMA jack (female socket)
connector
Feedline Trace

AEK-GNSSCP-SM12L1
www.linxtechnologies.com
Copyright © 2020 Linx Technologies

Figure 9. GNSSCP-SM12L1 Recommended Layout

7L1C2

L1C1

ANT-GNSSCP-SM12L1 GND

C1GND

Datasheet

Recommended Layout (Continued)
3-Element

4-Element
C1L1C1C2C2L1Figure 10. Matching Network Recommendation

Recommended PCB Footprint
Figure 11 shows the recommended printed circuit board footprint and spacing for the SM12L1 antenna. The
footprint recommendation should be used in conjunction with the recommended layout configuration shownin Figure 9.
8.5 mm(0.33 in)4x PCB Pads
3.5 mm x 3.5 mm(0.14 in x 0.14 in)

4.5 mm(0.18 in)
8.5 mm(0.33 in)
PCB Padfor antenna feed
3.0 mm x 3.0 mm(0.12 in x 0.12 in)Figure 11. ANT-GNSSCP-SM12L1 Antenna Placement on PCBTransmission Lines for Embedded Antennas
For most designs, Linx recommends a microstrip transmission line for the GNSSCP-SM12L1 antenna.
A microstrip transmission line is a PCB trace that runs over a ground plane to maintain the characteristic
impedance for optimal signal transfer between the antenna and radio circuitry. Linx designs all antennas witha characteristic impedance of 50 Ω.
Important practices to observe when designing a transmission line are:
•Keep all transmission lines to a minimum length for best signal performance.

•Use RF components that also operate at a 50 Ω impedance.

•If the radio is not on the same PCB as the antenna, the microstrip should be terminated in a connector,
enabling a shielded cable to complete the antenna connection to the radio.

•For designs subject to significant electromagnetic interference, a coplanar waveguide transmission line
may be used on the PCB.

The design of a PCB transmission line can be aided by many commercially available software packages
which can calculate the correct transmission line width and gap dimensions based upon the PCB thickness
and dielectric constant used. Linx offers PCB design reviews to help optimize solution performance.

8L2

Datasheet

ANT-GNSSCP-SM12L1Reflow Solder Profile
The ANT-GNSSCP-SM12L1 uses a typical RoHS solder reflow profile as shown in Figure 12. Refer toapplication note AN-00504 on the Linx website for more information.

Figure 12. Solder Profile for the GNSSCP-SM12L1 Antenna

9ANT-GNSSCP-SM12L1

Datasheet

Packaging Specifications
Figure 13 shows the dimensions of the tape in which the GNSSCP-TH12L1 antennas are packaged. Reeldimensions are provided in Figure 14.
P3P5P4

D1P2P6FWP1
D2T2T3T4

Tape Dimensions
Symbol Dimension (mm) Tolerance
D1Ø1.50± 0.10
D2
Ø2.00
± 0.10F12.40± 0.10P116.00± 0.10P228.40± 0.10P31.75± 0.10P44.00± 0.10P52.00± 0.10P614.20± 0.10
T20.35± 0.05
T312.40± 0.10T45.50± 0.10W
32.00± 0.30Figure 13. Tape Specifications for the GNSSCP-SM12L1 Antenna

W1

BCW

Reel Dimensions
SymbolSM12L1QTY per reel
500
Tape width32A
330.0 ±1.0B
Ø100 ±0.5C
Ø13 ±0.5
W33.0 ±1.00
W137.4 ±0.2

AFigure 14. Reel Specifications for the GNSSCP-SM12L1 Antenna

10Unitpcsmmmmmmmmmmmm

Datasheet
VSWR =10Return Loss
20+1

ANT-GNSSCP-SM12L1Return Loss
Antenna Definitions and Useful Formulas−11020VSWR - Voltage Standing Wave Ratio. VSWR is a unitless ratio that describes the power reflected from theantenna back to the radio. A lower VSWR value indicates better antenna performance at a given frequency.
VSWR is easily derived from Return Loss.

VSWR − 1Return Loss = −20
log10Loss
Return+ 1+ 110 Return
20 VSWRLossVSWR =10 Return20 Loss + 1
VSWR = 10−120Return Loss− 1 due to reflected signals, measured in
10Return Loss - Return loss represents the losspower
at 20the(G)antenna
10 logG in =db

10decibels. A lower return loss value indicates better antenna performance at a given frequency. Return Loss iseasily derived from VSWR.
GdBd = GdBi − 2.51dB
VSWR − 1Return Loss = −20 log10 VSWR − 1
VSWR + 1Return Loss = −20 log10VSWR + 1Return Loss2Efficiency (η) - The total power radiated from anVSWRantenna
bythe input power at the feed point of the+1
10 − divided
20
1
VSWR =antenna as a percentage.
(G)= 10Returnlog
Gdb VSWR
10Loss+ 120
1(G) −solution
10Gdb =10
Total Radiated Efficiency - (TRE) The total efficiencyof log
an 10antennacomprising the radiation=G−
2.51dBGdBiefficiency from the transmitter.
efficiency of the antenna and the transmitteddBd(forward)
GdBd = GdBi − 2.51dB 2VSWRVSWR−1 −1
LossTRELoss= η •= 1−ReturnReturn−20log
101110 VSWR
20 2 + +VSWR =VSWR − 1 VSWR + 1Return Loss
Gain - The ratio of an antenna’s efficiency in a given
direction
power produced by a theoreticalVSWR− 20
1 2(G) to−the
110 +VSWR
1lossless (100% efficient) isotropic antenna. The gain of an antenna is almost always expressed in decibels.

VSWR + 1
log10 (G)Gdb = 10/4

VSWR
VSWR
− 1 2− 1= −20
GdBi log−2.51dB
GdBd =ReturnLoss
TRE = η • 1 − VSWR
10−1 2frequency+1VSWR+1Peak Gain - The highest antenna gain TREacrossfor aVSWR
givenrange. A directional antenna= allη •directions
1−VSWR + 1will have a very high peak gain compared to average gain.
2Average Gain - The average gain across all directions
frequency range.
VSWRfor−a1given

log10 (G)Gdb = 10/4

Maximum Power - The maximum signal power which
VSWRmay+ 1be applied to an antenna feed point, typicallymeasured in watts (W).
GdBd = GdBi/4− 2.51dB

Reflected Power - A portion of the forward power reflected back toward the amplifier due to a mismatch atthe antenna port.
VSWR − 1 2TRE = η • 1 −VSWR −VSWR
1 2 +1VSWR + 1decibel (dB) - A logarithmic unit of measure of the power of an electrical signal.

/4

decibel isotropic (dBi) - A comparative measure in decibels between an antenna under test and an isotropic
VSWR − 1 2radiator.

TRE = η • 1 −VSWR+ 1 between an antenna under test anddecibel relative to a dipole (dBd) - A comparative measurein decibels
an ideal half-wave dipole.

Dipole - An ideal dipole comprises a straight electrical conductor measuring 1/2 wavelength from end to end
connected at the center to a feed point for the radio. /4
Isotropic Radiator - A theoretical antenna which radiates energy equally in all directions as a perfect sphere.
Omnidirectional - Term describing an antenna radiation pattern that is uniform in all directions. An
isotropic antenna is the theoretical perfect omnidirectional antenna. An ideal dipole antenna has a donutshaped radiation pattern and other practical antenna implementations will have less perfect but generally
omnidirectional radiation patterns which are typically plotted on three axes.

11ANT-GNSSCP-SM12L1

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Phone:
E-MAIL:

Datasheet

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159 Ort Lane, Merlin, OR, US 97532+1 (541) 471-6256
info@linxtechnologies.com

Linx Technologies reserves the right to make changes to the product(s) or information contained herein without notice. No liability is assumed as a result of their use
or application. No rights under any patent accompany the sale of any such product(s) or information.
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Copyright © 2020 Linx Technologies
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