Datasheet

ANT-GNSSCP-TH18L1
Ceramic Patch GNSS Antenna
The GNSSCP-TH18L1 is an 18 mm x 18 mm
square ceramic patch antenna for GPS/GLONASS/GALILEO/BeiDou global navigation satellite system(GNSS) operation. It provides excellent gain andradiation pattern performance supporting solutions
with high location accuracy, rapid satellite signal
reception and lock, and quick time to first fix.
The GNSSCP-TH18L1 offers an extended
temperature range to +105 °C for compliance toautomotive standard AEC-Q200 Grade 2. The
antenna is mounted via attached adhesive patch andhas a solder pin signal connection.

FeaturesApplications• Performance at 1567.24 MHz to 1583.60 MHz― VSWR: ≤ 2.8― Peak Gain: 5.1 dBi― Efficiency: 66%• Directional radiation pattern orthogonal toantenna surface• Right-hand circularly polarized (RHCP)• Extended operation to +105 °C• AEC-Q200 Grade 2 compliance• Adhesive mounting to PCB• Solder pin signal connection• Global navigation GNSS
― GPS L1
― Galileo E1― GLONASS I L1
― GLONASS II L1― Beidou B1-BOC― Beidou B1-2
― QZSS L1• Timing solutions• Automotive location

Ordering Information
Part Number
ANT-GNSSCP-TH18L1

Description
GNSS ceramic patch antenna with pin-type solder connection

Available from Linx Technologies and select distributors and representatives.

ANT-GNSSCP-TH18L1

Datasheet

Electrical Specifications
GNSSCP-TH18L1

GPS L1, GALILEO E1,
GLONASS II L1, Beidou B1BOC, QZSS L1

Beidou B1-2

GLONASS II L1

Center Frequency
1575.42 MHz
1589.74 MHz
1602 MHz
Frequency Range
1567.24 MHz to 1583.60 MHz 1587.69 MHz to 1591.79 MHz 1593.31 MHz to 1608.68 MHz
VSWR (max)
2.8
3.2
2.9Peak Gain (dBi)
5.1
2.8
4.0
10 Deg. Elevation (dBi)
2.5
1.7
1.3
Axial Ratio (dB)
12.2
9.6
12.3
Average Gain (dBi)
-2.2
-3.8
-2.3
Efficiency (%)
66
4465
Polarization
RHCP
Radiation
Omnidirectional
Max Power
8W
Wavelength
1/4-wave
Electrical Type
Ceramic Patch
Impedance
50 ΩConnection
Pin Type (Through hole)
Operating Temp. Range-40 °C to +105 °C
Weight6.0 g (0.21 oz)
Dimensions
18.0 mm x 18.0 mm x 4.0 (0.71 in x 0.71 in x 0.16 in)
ESD Sensitivity
NOT ESD sensitive. As a best practice, Linx may use ESD packaging.
Electrical specifications and plots measured with a 70 mm x 70 mm (2.76 in x 2.76 in) reference ground plane.

Product Dimensions
Figure 1 provides dimensions of the GNSSCP-TH18L1.

18.0 mm(0.71 in)

4.0 mm(0.16 in)

TECHNOLOGIESANT-GNSSCP-TH18L1v

Adhesive pad,NITTO 5015 adhesive
OD 16 mm (0.63 in)
ID 7.5 mm (0.30 in)
Thickness 0.12 mm (0.005 in)

18.0 mm(0.71 in)

1.7 mm(0.67 in)

1.8 mm(0.07 in)

Ø3.0 mm(0.12 in)Figure 1. GNSSCP-TH18L1 Antenna Dimensions2PinØ0.9 mm(0.04 in)

Datasheet

ANT-GNSSCP-TH18L1

VSWR

1609

1601
1602

1592
1593

1590

1587

1584

1575

51567

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.

VSWR43032021011560

1570

1580
1590
Frequency (MHz)

Reflected Power (%)

400
1610

1600

Figure 2. GNSSCP-TH18L1 VSWR

Return Loss

1609

1601
1602

1592
1593

1590

1587

1584

1575

0

1567

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-TH18L1 Return Loss

3

ANT-GNSSCP-TH18L1Datasheet

Peak Gain

1609

1601
1602

1592
1593

1590

1587

1584

1575

101567

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)50-5-101560

1570

1580
1590
Frequency (MHz)

1600

1610

Figure 4. GNSSCP-TH18L1 Peak Gain

Average Gain

Average Gain (dBi)1609

50-5-101560

1570

1580
1590
Frequency (MHz)Figure 5. GNSSCP-TH18L1 Antenna Average Gain

41601
1602

1592
1593

1590

1587

1584

1575

101567

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.

1600

1610

Datasheet

ANT-GNSSCP-TH18L1

Axial Ratio

1609

1601
1602

1592
1593

1590

1587

1584

1575

201567

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 TH18L1 antenna is shown in Figure 6.

Axial Ratio (dB)

1510501560

1570

1580
1590
Frequency (MHz)

1600

1610

Figure 6. Axial Ratio of the GNSSCP-TH18L1

Radiation Efficiency

1609

1601
1602

1592
1593

1590

1587

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 (%)

70
60
50
4030
201001560

1570

1580
1590
1600
Frequency (MHz)Figure 7. GNSSCP-TH18L1 Antenna Radiation Efficiency

1610

5ANT-GNSSCP-TH18L1

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)343533323130292836 50-5-10-15-20-25-30-35-40-45-50

123434533
632
731826
25

30
929

1028

11271226

2721

20

1918

17234345632
731830
929

1028

1127

1226

XZ-Plane Gain

21

20

1918

17

1234
5678
9101225

1324

15
2216

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

1114
2335

33

13

15
22

124

14
23

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

25

1324

35

1423

1615
2221

YZ-Plane Gain

20

1918

17

161567 MHz1576 MHz1584 MHz

XY-Plane Gain

1587.69 MHz to 1591.79 MHz (1590 MHz)
3435

3332313029
28

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

123434

533
632
731
826
25

29

1028

1127

1226

13
14
23

15
22

21

20

1918

XZ-Plane Gain

61716

30
92724

35

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

1234

34

533
632
731
825
1423

15
22

21

20

1918

17

YZ-Plane Gain

1630
9291028

1127

1226

1324

35

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

1234
5678910111225

1324

14
23152221

20

1918

17

XY-Plane Gain

161587 MHz
1590 MHz
1592 MHzDatasheet

ANT-GNSSCP-TH18L1

Radiation Patterns
1593.31 MHz to 1608.68 MHz (1601 MHz)
3435

33
32
31
30
29
28

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

123434

533
6

32
731
826
25

29

1028

1127

1226

13
14
23

15
22

21

20

19

18

1716

XZ-Plane Gain

30
9272435

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

1234

34

533632731825
1423

30
929102811271226

1324

2120

19

18

1736 50-5-10-15-20-25-30-35-40-45-50

12345678910111225

1324

15
22

35

16

YZ-Plane Gain

142315
22

21

20

19

18

1716

1593 MHz
1601 MHz1609 MHz

XY-Plane Gain

Figure 8. GNSSCP-TH18L1 Radiation Patterns

Ground Plane
Ceramic patch antennas are directional in signal transmission and reception orthogonal to the surface planeof the antenna, and require a ground plane for proper operation. The larger the ground plane, the narrowerthe 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.

Antenna Installation
The GNSSCP-TH18L1 attaches to the PCB surface using a double-sided adhesive (0.12 mm thick) which
consists of a flexible pressure sensitive adhesive that adheres to metal, plastic and other non-porous
surfaces. The mounting surface should be clean and free of moisture and oily residues for ideal adhesivestrength. The 4 optional PCB solder pads and their dimensions are provided for use where the adhesive
used to attach the antenna is not adequate to maintain the bond between the antenna and the PCB such as
in installations that are exposed to excessive vibration. To facilitate soldering the adhesive must be removed.

7

ANT-GNSSCP-TH18L1

ANT-GNSSCP-TH18L1

Datasheet

Recommended Layout
The recommended printed circuit board (PCB) layout for the GNSSCP-TH18L1 is demonstrated by the AEKGNSSCP-TH18L1 evaluation board shown in Figure 9. Contact Linx for availability of PCB layout design files.
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 theAEK-GNSSCP-TH18L1
www.linxtechnologies.com
evaluation board is optional,
the transmission line may be run directly to the radio if on the same PCB.
Copyright © 2020 Linx Technologies

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, as
designed, 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 components in the two capacitor positions. Thisis the configuration of the Linx evaluation board as supplied. Linx believes in wireless made simple® andoffers matching network design support.
PCB Top SidePCB Bottom Side

70x70mm

ANT-GNSSCP-TH18L1TECHNOLOGIESANT-GNSSCP-TH18L1

Pi matching circuit
C2

ANTENNAC1

SMA jack
2-Element(femalesocket)

L1

L1
C2

Ground plane
L1 layeron bottom
for counterpoiseC1C1

AEK-GNSSCP-TH18L1
www.linxtechnologies.com
Copyright © 2020 Linx Technologies

GNDGND

Figure 9. ANT-GNSSCP-TH18L1 Recommended Layout
3-Element
L1C14-Element

C1C2C2L1L2Figure 10. Matching Network Recommendation

C2L1C18

Datasheet

ANT-GNSSCP-TH18L1Recommended PCB Footprint
Figure 11 shows the recommended printed circuit board footprint for the GNSSCP-TH18L1 antenna. Thefootprint recommendation should be used in conjunction with the recommended layout configuration shownin Figure 9.
PCB Bottom Side
Detail ViewScale 2 : 1
PCB Top SideC2

11.5 mm(0.45 in)

L1

1.8 mm(0.07 in)C2
Through holefor antenna feed
Ø0.95 mm (0.04 in)
C1

L1

C1

11.5 mm(0.45 in)4x PCB Solder Pads
6.5 mm x 6.5 mm(0.26 in x 0.26 in)Figure 11. ANT-GNSSCP-TH18L1 Antenna Placement on PCBTransmission Lines for Embedded Antennas
For most designs, Linx recommends a microstrip transmission line for the GNSSCP-TH18L1 antenna. Amicrostrip 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.

9

ANT-GNSSCP-TH18L1

Datasheet

Packaging Specifications
The GNSSCP-TH18L1 antennas are packaged in protective plastic trays as shown in Figure 12. Antennas
are packaged 25 per tray, 200 antennas (8 trays) are packed in a carton 10.4 in x 6.1 in x 3.8 in (263 mm x154 mm x 96 mm). 800 antennas packaged in a shipping box 12.9 in x 11.0 in x 8.6 in (327 mm x 280 mm x218 mm).

Top View

Front View

Figure 12. Packaging Specifications for the ANT-GNSSCP-TH18L1

10

Datasheet
VSWR =10

Return Loss
20+1

ANT-GNSSCP-TH18L1

Return 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 − 1
Return Loss = −20
log10Loss
Return+ 1+ 1
10 Return20 VSWRLoss
VSWR =
10 Return20 Loss + 1
VSWR = 10−1
20Return 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 − 1

Return Loss = −20 log10 VSWR − 1
VSWR + 1
Return Loss = −20 log10
VSWR + 1
Return Loss
2Efficiency (η) - The total power radiated from anVSWR
antennabythe input power at the feed point of the+1
10 − divided
201VSWR =antenna as a percentage.
(G)= 10Returnlog
Gdb VSWR
10Loss+ 120
1(G) −solution
10Gdb =10Total 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 −1LossTRELoss= η •= 1−Return
Return−20log
101110 VSWR
20 2 + +VSWR =VSWR − 1 VSWR + 1
Return Loss
Gain - The ratio of an antenna’s efficiency in a given
direction
power produced by a theoretical
VSWR− 201 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 + 1
will 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 + 1

decibel (dB) - A logarithmic unit of measure of the power of an electrical signal.

/4decibel 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 measure
in 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-TH18L1

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Datasheet

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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.
Wireless Made Simple is a registered trademark of Linx Acquisitions LLC. Other product and brand names may be trademarks or registered trademarks of theirrespective owners.
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All Rights Reserved
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