GPDF254.A

+ v c ed a a a) + © C) 

|1.|Introduction|3|
|---|---|---|
|2.|Specifications|4|
|3.|Passive Antenna Characteristics|6|
|4.|Radiation Patterns|11|
|5.|Field Test Data|15|
|6.|Mechanical Drawing|17|
|7.|Evaluation Board Mechanical Drawing|18|
|8.|Antenna Integration Guide|19|
|9.|Evaluation Board Matching Circuit|22|
|10. Packaging|10. Packaging|23|
||Changelog|24|



Taoglas makes no warranties based on the accuracy or completeness of the contents of this document and reserves the right to make changes to specifications and product descriptions at any time without notice. Taoglas reserves all rights to this document and 

the information contained herein. Reproduction, use or disclosure to third parties without express permission is strictly prohibited. 

www.taoglas.com 

SPE-20-8-101-B 

2 

## **1** . Introduction 

The GPDF254.A is a high performance, single-band passive GNSS L1 antenna that has been carefully designed to provide fantastic positional accuracy on the full GNSS L1 spectrum. It has a dual feed, passive patch design which makes it ideal for next-generation GNSS devices that require excellent positional accuracy in a small form factor. The patch antenna, by means of a double resonance design, has a wide-band operation over GNSS systems including GPS (L1), GLONASS (G1), Galileo (E1) and BeiDou(B1). The 25 mm patch uses a dualfeed configuration to obtain an optimal axial ratio. The GPDF254.A is manufactured and tested in a TS16949 first tier automotive approved facility. 

Typical applications include: 

- High accuracy positioning and navigation systems 

- UAVs, Robotics & Autonomous Vehicles 

- Transportation & Telematics 

- Precision Agriculture 

- RTK Systems 

The GPDF254.A is the latest embedded addition to Taoglas’ product portfolio of high precision GNSS antennas. When used on the base and/or the rover as part of an RTK configuration, the GPDF254.A can achieve genuine cm-level accuracy with proven results. 

Full integration guidelines are contained in Section 8 of this datasheet including the Taoglas HC125.A hybrid coupler that will be required for use for dual pin feed patch integrations. Two active versions of this antenna, the ADFGP.25A.07.0100C – tuned for a 70*70mm Ground Plane and ADFGP.25E.07.0100C – tuned for free space is available and supplied with 100mm cable and I-PEX MHFI connector as standard. 

Contact your local Taoglas Customer Services team for more information on any of the products listed above or for support regarding integration. 

www.taoglas.com 3 

SPE-20-8-101-B 

## **2.** Specifications 

|**GNSS Frequency Bands Covered**|**GNSS Frequency Bands Covered**|**GNSS Frequency Bands Covered**|**GNSS Frequency Bands Covered**|**GNSS Frequency Bands Covered**|**GNSS Frequency Bands Covered**|
|---|---|---|---|---|---|
|**GPS**|L1|L2|L5|||
||▓|□|□|||
|**GLONASS**|G1|G2|G3|||
||▓|□|□|||
|**Galileo**|E1|E5a|E5b|E6||
||▓|□|□|□||
|**BeiDou**|B1|B2a|B2b|B3||
||▓|□|□|□||
|**QZSS (Regional)**|L1|L2C|L5|L6||
||▓|□|□|□||
|**IRNSS**<br>**(Regional)**|L5|||||
||□|||||
|**SBAS**|L1/E1/B1|L5/B2a/E5a|G1|G2|G3|
||▓|□|▓|□|□|



*SBAS systems: WASS(L1/L5), EGNOSS(E1/E5a), SDCM(G1/G2/G3), SNAS(B1,B2a), GAGAN(L1/L5), QZSS(L1/L5), KAZZ(L1/L5). 

## GNSS Bands and Constellations 

www.taoglas.com 

SPE-20-8-101-B 

4 

||**GNSS Electrical**|**GNSS Electrical**|**GNSS Electrical**|
|---|---|---|---|
|**Frequency (MHz)**|**1561**|**1575.42**|**1602**|
|Return Loss (dB)|< -10|< -10|< -10|
|Efficiency (%)|39.6|53.8|38|
|Peak Gain (dBi)|1.4|3.1|1.7|
|Average Gain (dB)|-4|-2.7|-4.2|
|Axial Ratio (dB)|0.9|0.7|0.54|
|Polarization|R.H.C.P.|||
|Impedance|**50**Ω|||



Note. The patch antenna is tested with hybrid coupler HC125 and tuned on 70x70(mm) ground plane. 

||**Mechanical**|
|---|---|
|Ceramic Dimension|25 x 25 x 4.0 mm|
|Pin Length|2.4mm|
|Weight|9.7 g|
||**Environmental**|
|Operation Temperature|-40°C to 85°C|
|Storage Temperature|-40°C to 85°C|
|Humidity|Non-condensing 65°C 95% RH|



www.taoglas.com 5 

SPE-20-8-101-B 

## **3.** Passive Antenna Characteristics 

## **3.1** Return Loss for single pin without coupler ff 

**==> picture [462 x 242] intentionally omitted <==**

**----- Start of picture text -----**<br>
0<br>-5<br>-10<br>-15<br>-20<br>-25<br>1400 1450 1500 1550 1600 1650 1700 (MHz)<br>(dB)<br>**----- End of picture text -----**<br>


## 4 **3.2** Return Loss For dual pin with coupler 

**==> picture [460 x 221] intentionally omitted <==**

**----- Start of picture text -----**<br>
0<br>-5<br>-10<br>-15<br>-20<br>-25<br>1400 1450 1500 1550 1600 1650 1700 (MHz)<br>(dB)<br>**----- End of picture text -----**<br>


www.taoglas.com 

SPE-20-8-101-B 

6 

## of **3.3** Efficiency for single pin without coupler 

**==> picture [456 x 267] intentionally omitted <==**

**----- Start of picture text -----**<br>
100%<br>90%<br>| | | |hE<br>80%<br>| | | |6<br>70%<br>_| | | | ee<br>60%<br>ee ee ee ee<br>50%<br>_ | | | |ING<br>40%<br>— | | | |UO<br>30%<br>— | | | |OYUN<br>20%<br>_ | | | TY [EN]<br>10%<br>| | YY a SN<br>aOS<br>0%<br>1.40 1.44 1.48 1.51 1.55 1.59 1.63 1.66 1.70<br>Frequency [GHz]<br>**----- End of picture text -----**<br>


## **3.4** Efficiency for dual pin with coupler ff 

**==> picture [451 x 268] intentionally omitted <==**

**----- Start of picture text -----**<br>
100%<br>90%<br>P| ft | tt a |<br>80%<br>P|} |} tt Ta<br>70%<br>P|} |} tt Ta<br>60%<br>P|} | tt Ta<br>RR). Eee<br>50%<br>40%<br>P| | | tt Te<br>30%<br>pj ft | | | ASA<br>20%<br>P| tT | |YN<br>10%<br>pt | | | | er | | ND|<br>Seeeee)<br>0%<br>| ae<br>1.40 1.44 1.48 1.51 1.55 1.59 1.63 1.66 1.70<br>Frequency [GHz]<br>**----- End of picture text -----**<br>


www.taoglas.com 

SPE-20-8-101-B 

7 

## **3.5** Average Gain for single pin without coupler of 

**==> picture [455 x 267] intentionally omitted <==**

**----- Start of picture text -----**<br>
0<br>-1<br>-2<br>_ || | | | Eeee |<br>-3<br>_ | | | YIN<br>| | | |he<br>-4<br>| | | | AR |<br>-5<br>-6<br>_ | | | /ERY |<br>-7<br>_ | | | f/ A<br>-8<br>_ | | |/ Eee \<br>-9<br>| | | YY Eee \<br>-10<br>— | | yf Ee A<br>1.40 1.44 1.48 1.51 1.55 1.59 1.63 1.66 1.70<br>Frequency [GHz]<br>**----- End of picture text -----**<br>


## | **3.6** Average Gain for dual pin with coupler 

**==> picture [474 x 267] intentionally omitted <==**

**----- Start of picture text -----**<br>
0<br>-1<br>ei; | i ft | | Ta<br>eee) ae<br>-2<br>-3 | | | | | | | ee<br>-4<br>| | | | | |)<br>| | | | | |LAR<br>-5<br>-6<br>ees) hee<br>| | | | | AT A<br>-7<br>-8 | | i | | |TN<br>-9<br>| | i | | Tf | A<br>-10<br>i | i | | 7) [PN]<br>1.40 1.44 1.48 1.51 1.55 1.59 1.63 1.66 1.70<br>Frequency [GHz]<br>**----- End of picture text -----**<br>


www.taoglas.com 8 

SPE-20-8-101-B 

## **3.7** Peak Gain for single pin without coupler _ 

**==> picture [462 x 267] intentionally omitted <==**

**----- Start of picture text -----**<br>
5<br>| | | | im | |<br>4<br>|<br>3<br>2<br>| | | | | Qa ||<br>1<br>| | | | | ARR |<br>| | | | /TR, ||<br>0<br>-1<br>-2<br>| | | |} UY UA<br>-3<br>| | | | | /f/ PT m \NV<br>-4<br>| |<br>-5<br>| | | | fsYY EeJ AIN<br>1.40 1.44 1.48 1.51 1.55 1.59 1.63 1.66 1.70<br>Frequency [GHz]<br>**----- End of picture text -----**<br>


## **3.8** Peak Gain for dual pin with coupler 4 

**==> picture [457 x 267] intentionally omitted <==**

**----- Start of picture text -----**<br>
5<br>4<br>RRs 6) lh [hee]<br>eee) ae<br>3<br>eee eee) oO) eee<br>2<br>1<br>|| | | | | | | TL Ae<br>0<br>|| | | |) | | VSN<br>-1<br>|| | | |) | dT A a A<br>-2<br>|| | | | |] | l/ | aN<br>-3<br>pi | tt i | YT TAT<br>-4<br>|| | | | | dt) | a AT<br>-5<br>|| | | td) UY Ta |<br>1.40 1.44 1.48 1.51 1.55 1.59 1.63 1.66 1.70<br>Frequency [GHz]<br>**----- End of picture text -----**<br>


www.taoglas.com 

SPE-20-8-101-B 

9 

**==> picture [475 x 315] intentionally omitted <==**

**----- Start of picture text -----**<br>
3.9 Axial Ratio at Phi=0<br>_<br>phi = 0<br>9.0<br>TE<br>eseeeee<br>6.0<br>ee [ee][eee] |<br>ey eeee|<br>eeee<br>es ee \<br>3.0<br>ee<br>Sf SwAY<br>ST NAS EN YY<br>NE<br>0.0<br>-180 -120 -60 0 60 120 180<br>Angle [Deg]<br>1575.42MHz 1561MHz 1602MHz<br>**----- End of picture text -----**<br>


## **3.10** Axial Ratio at Phi=90 _ 

**==> picture [464 x 281] intentionally omitted <==**

**----- Start of picture text -----**<br>
phi = 90<br>9.0<br>A |<br>Oe | ee ee<br>|<br>EW<br>6.0<br>NW<br>ee eee<br>|<br>3.0<br>a Ae<br>am)<br>4) \Gee en<br>AP VNeeeZNVES<br>0.0<br>-180 -120 -60 0 60 120 180<br>Angle [Deg]<br>1575.42MHz 1561MHz 1602MHz<br>**----- End of picture text -----**<br>


www.taoglas.com 

SPE-20-8-101-B 

10 

## **4.** Radiation Patterns 

**==> picture [102 x 13] intentionally omitted <==**

**----- Start of picture text -----**<br>
4.1 Test Setup<br>**----- End of picture text -----**<br>


**==> picture [60 x 103] intentionally omitted <==**

**----- Start of picture text -----**<br>
Y<br>X<br>Z<br>**----- End of picture text -----**<br>


Note. The patch antenna test with hybrid coupler HC125.A and tuned on 70x70(mm) ground plane. 

www.taoglas.com 

SPE-20-8-101-B 

11 

## **4.2** 1561MHz 3D and 2D Radiation Patterns 

## XZ Plane 

## YZ Plane 

www.taoglas.com 

SPE-20-8-101-B 

12 

**==> picture [289 x 11] intentionally omitted <==**

**----- Start of picture text -----**<br>
4.3 1575.42MHz 3D and 2D Radiation Patterns<br>**----- End of picture text -----**<br>


## XZ Plane YZ Plane ~~ee ee~~ 

www.taoglas.com 

SPE-20-8-101-B 

13 

**==> picture [272 x 11] intentionally omitted <==**

**----- Start of picture text -----**<br>
4.4 1602MHz 3D and 2D Radiation Patterns<br>**----- End of picture text -----**<br>


## XZ Plane 

## YZ Plane 

www.taoglas.com 

SPE-20-8-101-B 

14 

## **5.** Field Test Results 

In this section Taoglas will present the field test result for GPDF254.A antenna. The test was performed when the antenna was mounted on a static rooftop test set up in an open sky environment for at least 6 hours. 

Taoglas will show the field test results using the following receivers: 

## **5.1** Ublox ZED-F9P 

## Receiver features: 

- Multi-band GNSS: 184-channel GPS L1C/A L2C, GLONASS: L1OF L2OF, Galileo: E1B/C E5b, BeiDou: B1I B2I, QZSS: L1C/A L2C 

- Multi ‑ band RTK with fast convergence times and reliable performance 

- Nav. update rate RTK up to 20 Hz 

- Position accuracy = RTK 0.01 m + 1 ppm CEP 

|**Positioning Accuracy Table(2D Accuracy)**<br>~~ee~~|**Positioning Accuracy Table(2D Accuracy)**<br>~~ee~~|**Positioning Accuracy Table(2D Accuracy)**<br>~~ee~~|**Positioning Accuracy Table(2D Accuracy)**<br>~~ee~~|**Positioning Accuracy Table(2D Accuracy)**<br>~~ee~~|**Positioning Accuracy Table(2D Accuracy)**<br>~~ee~~|
|---|---|---|---|---|---|
|**Test**<br>**Condition**<br>~~ee~~|**Correction**<br>**Service**<br>~~ee~~|**CEP (50%)**<br>~~ee~~|**DRMS (68%)**<br>~~ee~~|**2DRMS (95-98.2%)**<br>~~ee~~|**TTFF (sec)**<br>~~ee~~|
|**On**<br>**70*70mm**<br>**EVB**|RTK DISABLED|63.58 cm|79.96 cm|159.92 cm|18|
||RTK ENABLED|0.66 cm|0.79 cm|1.59 cm|18|



www.taoglas.com 

SPE-20-8-101-B 

15 

## **5.2** Ublox NEO-M8P 

## Receiver features: 

- Multi-band GNSS: 72 channels ublox M8 engine 

- GPS: L1 C/A GLONASS: L1OF BeiDou: B1, Not support RTK 

- Nav. update rate up to 8 Hz (RTK) 

- Carrier phase data up to 10Hz 

- Position accuracy = 

- Standalone: 2.5m CEP 

- RTK 0.025 m + 1 ppm CEP 

|•<br>**Positioning Accuracy Table(2D Accuracy)**|•<br>**Positioning Accuracy Table(2D Accuracy)**|•<br>**Positioning Accuracy Table(2D Accuracy)**|•<br>**Positioning Accuracy Table(2D Accuracy)**|•<br>**Positioning Accuracy Table(2D Accuracy)**|•<br>**Positioning Accuracy Table(2D Accuracy)**|
|---|---|---|---|---|---|
|**Test**<br>**Condition**|**Correction**<br>**Service**|**CEP (50%)**|**DRMS (68%)**|**2DRMS (95-98.2%)**|**TTFF (sec)**|
|**On**<br>**70*70mm**<br>**EVB**|RTK DISABLED|66.26 cm|81.71 cm|163.43 cm|30|
||RTK ENABLED|2.39 cm|3 cm|6.01 cm|30|



www.taoglas.com 

SPE-20-8-101-B 

16 

## **6.** Mechanical Drawing (Units: mm) 

www.taoglas.com 17 

SPE-20-8-101-B 

## **7.** Evaluation Board Mechanical Drawing (Units: mm) 

www.taoglas.com 18 

SPE-20-8-101-B 

## **8.** Antenna Integration Guide 

## **8.1** Integration Guide 

Whatever the size of the PCB, the ideal location for the antenna is as illustrated in the below diagram; on the PCB’s shortest side, in the left corner. This allows placement of the optimized matching components alongside the antenna. 

www.taoglas.com 19 

SPE-20-8-101-B 

## **8.2** PCB Layout = 

The footprint and clearance on the PCB must comply with the antenna specification. The PCB layout shown in the diagram below demonstrates the antenna footprint. 

## Topside 

## Bottom Side 

## **8.3** PCB Layout _ 

www.taoglas.com 

SPE-20-8-101-B 

20 

**8.4** Schematic Symbol and Pin Definitions 

The circuit symbol for the antenna is shown below. The antenna has 2 pins that are orthogonal feeds. 

|Pin<br>~~EEE~~|Description<br>~~EEE~~|
|---|---|
|1|L1P1 (0°)|
|2|L1P2 (-90°)|



www.taoglas.com 

SPE-20-8-101-B 

21 

## **9.** Evaluation Board Matching Circuit 

The antenna patch element uses two orthogonal feeds that are combined in a hybrid coupler to ensure optimal axial ratio. A hybrid coupler is required for this antenna and should be included in the design. The hybrid coupler should be placed close to the antenna pins and terminated correctly using 2x 100 ohm resistors in parallel. 

|**Matching Components**|**Matching Components**|**Matching Components**|**Matching Components**|
|---|---|---|---|
|Designator|Type|Value|Description|
|R1, R2|Resistor (0402)|100Ω (1%)|Yageo RT0402BRE07100RL|
|X1|Hybrid Coupler|HC125A|Taoglas|



www.taoglas.com 22 

SPE-20-8-101-B 

## **8.10. Packaging** 

50pcs GPDF254.A per Tray Weight: 520g 

200pcs GPDF254.A per Inner Carton Dimensions: 261*152*118 mm Weight: 2.5Kg 

800pcs GPDF254.A per Carton Dimensions: 330*280*270 mm Weight: 10.2Kg 

www.taoglas.com 

SPE-20-8-101-B 

23 

Changelog for the datasheet **SPE-20-8-101-A – GPDF254.A** 

**Revision: B (Current Version)** Date: 2023-02-21 Changes: Updated GNSS Bands & Constellations Graphics Changes Made by: Cesar Sousa 

## **Previous Revisions** 

**Revision: A** Date: 2020-10-14 Changes: Initial Release Changes Made by: David Connolly 

www.taoglas.com 

SPE-20-8-101-B 

24 

www.taoglas.com 

© Taoglas 

www.taoglas.com 25 

SPE-20-8-101-B