HA.21.A

Helical Antenna, 850MHz to 880MHz, 2dBi Gain, 50ohm, Linear Polarisation, PCB

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Manufacturer: TAOGLAS
Product type:
Antenna Type:Helical; Frequency Min:850MHz; Frequency Max:880MHz; Antenna Mounting:PCB; Gain:2dBi; VSWR:-; Input Power:-; Input Impedance:50ohm; Antenna Polarisation:Linear; Product Ran
Gain: 2dBi
SVHC: To Be Advised
VSWR: -
Input Power: -
Antenna Type: Helical
Frequency Max: 880MHz
Frequency Min: 850MHz
Product Range: -
Input Impedance: 50ohm
Antenna Mounting: PCB
Antenna Polarisation: Linear

Delivery and price
Units per pack	100
Price	0.783 €
Current stock	10+
Lead time	30 days

Datasheet

## **SPECIFICATION** 

## **Part No.** 

## : **HA.21.A** 

## **Description** 

- : 2dBi 868MHz Embedded Helical Monopole Antenna 

## **Features** 

: Quarter-wave Monopole Type Helical Antenna 868 MHz ISM Band Omni-Directional 2dBi peak gain and 70% efficiency Direct mounted on board design Mechanically sturdy in a compact size Dimensions: 11mm, Ø10.25mm RoHS compliant 

DSP-15-8-SPE-16-8-016/B/WY     Page **1** of **25** 

## **1. Introduction** 

The HA.21.A is an ISM 868MHz quarter-wave monopole helical antenna. Small and compact, yet stable, this helical coil antenna is ideal for typical 868MHz applications such as: 

- Smart Metering 

- Smart security systems 

- Remote asset monitoring and other wireless communication devices. 

The helical coil antenna offers industry leading 70% efficiency at 868MHz on a 126.8 x 80.1mm ground plane, with matching components (orthogonally mounted to ground plane, see HAD.B.21 performance). Made of copper alloy, the helical coil is mechanically sturdy. It can be easily mounted on the surface by soldering.  Since it is a monopole design, it must be connected to the main-board device ground-plane to radiate efficiently. 

DSP-15-8-SPE-16-8-016/B/WY     Page **2** of **25** 

Taoglas has two models of evaluation boards, HAD.A.21 and HAD.B.21, to show performance when the antenna is parallel mounted, or orthogonally mounted to the ground plane. 

Small embedded antennas can easily detune or lose efficiency on different board and in different device environments. Taoglas offers a testing and tuning service for custom antennas, subject to NRE and MOQ. Please contact your regional Taoglas office for support. 

DSP-15-8-SPE-16-8-016/B/WY     Page **3** of **25** 

## **2. Specification** 

|ELECTRICAL<br>~~LO~~|ELECTRICAL<br>~~LO~~|ELECTRICAL<br>~~LO~~|ELECTRICAL<br>~~LO~~|ELECTRICAL<br>~~LO~~|ELECTRICAL<br>~~LO~~|ELECTRICAL<br>~~LO~~|
|---|---|---|---|---|---|---|
|Application Bands|ISM 868MHz||||||
|Mounting Direction|HAD.A.21|||HAD.B.21|||
|Frequency (MHz)<br>Return Loss (dB)<br>Peak Gain (dBi)|850<br>868<br>880<br>850<br>868<br>880<br><-10<br>0.76<br>0.77<br>0.27<br>1.79<br>1.83<br>1.64||||||
|Average Gain (dBi)|-2.82|-2.87|-3.35|-1.42|-1.49|-1.74|
|Efficiency (%)<br>Polarization|52.21<br>51.52<br>46.22<br>72.10<br>70.95<br>66.92<br>Linear||||||
|Impedance|50 ohms||||||
|MECHANICAL<br>~~Lo~~|||||||
|Helical Coil Dimension|L: 11mm, Ø10.25mm||||||
|Weight (g)|0.7||||||
|ENVIRONMENTAL<br>Operation Temperature<br>-40°C to 85°C<br>~~Lo~~|||||||
|Humidity|Non-condensing 65°C 95% RH||||||



DSP-15-8-SPE-16-8-016/B/WY     Page **4** of **25** 

## **3. Antenna Characteristics** 

## **3.1 Return Loss** 

## **3.2 Efficiency** 

DSP-15-8-SPE-16-8-016/B/WY     Page **5** of **25** 

## **3.3 Average Gain** 

## **3.4 Peak Gain** 

DSP-15-8-SPE-16-8-016/B/WY     Page **6** of **25** 

## **4. Antenna Radiation Pattern** 

## **4.1. Measurement Setup** 

The HA.21 antenna is tested on HAD.A.21 and HAD.B.21in a CTIA certified ETS-Lindgren Anechoic Chamber. The test setup is shown below. 

DSP-15-8-SPE-16-8-016/B/WY     Page **7** of **25** 

## **4.2. 2D Radiation Pattern** 

## - **On HAD.A.21** 

XY Plane 

**==> picture [142 x 135] intentionally omitted <==**

**----- Start of picture text -----**<br>
X<br>0<br> ee ~~ 30<br>SC \ \60<br> LY s \ \ \<br>Y<br>**----- End of picture text -----**<br>


## XZ Plane 

**==> picture [143 x 130] intentionally omitted <==**

**----- Start of picture text -----**<br>
Z<br>U<br>i 30<br>|KO > 60<br>X<br>**----- End of picture text -----**<br>


DSP-15-8-SPE-16-8-016/B/WY     Page **8** of **25** 

**==> picture [305 x 148] intentionally omitted <==**

**----- Start of picture text -----**<br>
YZ Plane<br>Z<br>0<br>330. \ / 30<br>\ AN 5 ’ /<br>[— > tt NS 3 | Lf Se a a<br>Y<br>**----- End of picture text -----**<br>


## - **On HAD.B.21** 

- XY Plane 

**==> picture [12 x 9] intentionally omitted <==**

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


**==> picture [12 x 9] intentionally omitted <==**

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


DSP-15-8-SPE-16-8-016/B/WY     Page **9** of **25** 

- XZ Plane 

**==> picture [323 x 420] intentionally omitted <==**

**----- Start of picture text -----**<br>
Z<br>0<br>330. \ / 30<br>300 ¢ C x \ ly 60<br>X<br>240 < J A | Vx \ Y 120<br>210° / \ “450<br>180<br>(dBi)<br>-<br>YZ Plane<br>Z<br>0<br>330, \ / 30<br>300 < YK XT \ er, S60<br>270 = —- 90 Y<br>**----- End of picture text -----**<br>


DSP-15-8-SPE-16-8-016/B/WY     Page **10** of **25** 

## **4.3. 3D Radiation Pattern** 

## - **On HAD.A.21** 

## @868MHz 

## - **On HAD.B.21** 

## @868MHz 

DSP-15-8-SPE-16-8-016/B/WY     Page **11** of **25** 

## **5. Mechanical Drawing** 

## **5.1 HA.21.A Antenna** 

Unit: mm 

## **Foot-Print** 

DSP-15-8-SPE-16-8-016/B/WY     Page **12** of **25** 

## **5.2 HAD.A.21 Evaluation Board** 

DSP-15-8-SPE-16-8-016/B/WY     Page **13** of **25** 

DSP-15-8-SPE-16-8-016/B/WY     Page **14** of **25** 

## **5.3 HAD.B.21 Evaluation Board** 

Unit: mm 

DSP-15-8-SPE-16-8-016/B/WY     Page **15** of **25** 

## **6. Packaging** 

## **6.1. HAD.A.21** 

DSP-15-8-SPE-16-8-016/B/WY     Page **16** of **25** 

## **6.2. HAD.B.21** 

DSP-15-8-SPE-16-8-016/B/WY     Page **17** of **25** 

## **6.3. HA.21.A** 

DSP-15-8-SPE-16-8-016/B/WY     Page **18** of **25** 

## **7. Antenna Application Note** 

## **7.1 Matching Circuit for Different Ground Lengths** 

## **7.1.1 HAD.A.21 EVB Board** 

|HAD.A.21<br>~~a~~|Ceramic 4<br>~~a~~|Ceramic 5<br>~~a~~|Ceramic 6<br>~~a~~|
|---|---|---|---|
|160mm|0 ohm|2.2pF|0 ohm|
|150mm|0 ohm|2.2pF|0 ohm|
|140mm|0 ohm|2.2pF|0 ohm|
|130mm|0 ohm|2.2pF|0 ohm|
|120mm|0 ohm|2.2pF|0 ohm|
|110mm|0 ohm|2.4pF|0 ohm|
|100mm|0 ohm|2.4pF|0 ohm|
|90mm|0 ohm|2.4pF|0 ohm|
|80mm|0 ohm|2.4pF|0 ohm|
|70mm|0 ohm|2.4pF|1nH|
|60mm|0 ohm|2.4pF|1nH|
|50mm|0 ohm|2.4pF|1nH|



## **7.1.2 HAD.B.21 EVB Board** 

|HAD.B.21|Ceramic 4|Ceramic 5|Ceramic 6|
|---|---|---|---|
|160mm|0 ohm|2.2pF|5.6nH|
|150mm|0 ohm|2.2pF|9.1nH|
|140mm|0 ohm|2.2pF|9.1nH|
|130mm|0 ohm|3.3pF|10nH|
|120mm|0 ohm|3.6pF|10nH|
|110mm|0 ohm|open|2.2pF|
|100mm|0 ohm|open|2.2pF|
|90mm|0 ohm|open|2.2pF|



DSP-15-8-SPE-16-8-016/B/WY     Page **19** of **25** 

## **7.2 Return loss** 

## **7.2.1 HAD.A.21 EVB board** 

## **7.2.2 HAD.B.21 EVB board** 

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## **7.3 Efficiency 7.3.1 HAD.A.21 EVB Board (Different Ground Length)** 

## **7.3.2 HAD.B.21 EVB Board (Different Ground Length)** 

DSP-15-8-SPE-16-8-016/B/WY     Page **21** of **25** 

## **7.4 Average Gain** 

## **7.4.1 HAD.A.21 EVB Board (Different Ground Length)** 

## **7.4.2 HAD.B.21 EVB Board (Different Ground Length)** 

DSP-15-8-SPE-16-8-016/B/WY     Page **22** of **25** 

## **7.5 Peak Gain** 

## **7.5.1 HAD.A.21 EVB Board (Different Ground Length)** 

## **7.5.2 HAD.B.21 EVB Board (Different Ground Length)** 

DSP-15-8-SPE-16-8-016/B/WY     Page **23** of **25** 

## **7.6 Antenna Performance Table** 

|ELECTRICAL<br>~~Lo~~|ELECTRICAL<br>~~Lo~~|ELECTRICAL<br>~~Lo~~|ELECTRICAL<br>~~Lo~~|ELECTRICAL<br>~~Lo~~|ELECTRICAL<br>~~Lo~~|ELECTRICAL<br>~~Lo~~|
|---|---|---|---|---|---|---|
|Application Bands|ISM 868MHz||||||
|Mounting Direction|HAD.A.21|||HAD.B.21|||
|Frequency (MHz)|850|868|880|850|868|880|
|Efficiency|||||||
|Ground plane length 160mm|47.48|52.89|48.66|69.27|65.15|59.04|
|Ground plane length 150mm|50.33|59.00|54.64|67.34|66.93|63.18|
|Ground plane length 140mm|50.73|60.42|55.73|63.08|64.60|62.80|
|Ground plane length 130mm|55.38|59.44|49.44|59.41|63.21|61.23|
|Ground plane length 120mm|50.02|59.18|54.98|55.94|60.70|59.82|
|Ground plane length 110mm|42.92|49.87|45.21|54.65|60.55|61.17|
|Ground plane length 100mm|34.92|45.20|44.64|42.34|57.28|56.70|
|Ground plane length 90mm|32.98|44.25|42.92|36.15|52.23|53.23|
|Ground plane length 80mm|26.56|38.42|41.24|X|X|X|
|Ground plane length 70mm|23.03|35.84|39.12|X|X|X|
|Ground plane length 60mm|23.07|35.06|36.05|X|X|X|
|Ground plane length 50mm|23.46|33.66|33.44|X|X|X|
|Average Gain(dBi)|||||||
|Ground plane length 160mm|-3.23|-2.77|-3.12|-1.59|-1.86|-2.28|
|Ground plane length 150mm|-2.98|-2.29|-2.62|-1.71|-1.74|-1.99|
|Ground plane length 140mm|-2.94|-2.19|-2.53|-2.00|-1.90|-2.01|
|Ground plane length 130mm|-2.56|-2.26|-3.05|-2.26|-1.99|-2.13|
|Ground plane length 120mm|-3.00|-2.28|-2.59|-2.52|-2.17|-2.23|
|Ground plane length 110mm|-3.67|-3.02|-3.44|-2.62|-2.18|-2.13|
|Ground plane length 100mm|-4.56|-3.45|-3.50|-3.73|-2.42|-2.46|
|Ground plane length 90mm|-4.81|-3.54|-3.67|-4.41|-2.81|-2.73|
|Ground plane length 80mm|-5.75|-4.15|-3.84|X|X|X|
|Ground plane length 70mm|-6.37|-4.46|-4.07|X|X|X|
|Ground plane length 60mm|-6.36|-4.55|-4.43|X|X|X|
|Ground plane length 50mm|-6.29|-4.73|-4.75|X|X|X|



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|Peak Gain(dBi)<br>~~eee~~<br>~~es~~|Peak Gain(dBi)<br>~~eee~~<br>~~es~~|Peak Gain(dBi)<br>~~eee~~<br>~~es~~|Peak Gain(dBi)<br>~~eee~~<br>~~es~~|Peak Gain(dBi)<br>~~eee~~<br>~~es~~|Peak Gain(dBi)<br>~~eee~~<br>~~es~~|Peak Gain(dBi)<br>~~eee~~<br>~~es~~|
|---|---|---|---|---|---|---|
|Ground plane length 160mm<br>~~ss~~|-0.87<br>~~ss~~<br>~~ds~~|0.51<br>~~ss~~<br>~~es~~<br>~~ds~~|0.69<br>~~ss~~|1.54<br>~~ss~~|1.45<br>~~ss~~|1.08<br>~~ss~~|
|Ground plane length 150mm<br>~~es~~|-0.67<br>~~es~~<br>~~ds~~<br>~~de~~|1.01<br>~~es~~<br>~~es~~<br>~~ds~~<br>~~de Gs~~|1.22<br>~~es~~<br>~~Gs~~|1.28<br>~~es~~|1.39<br>~~es~~|1.19<br>~~es~~|
|Ground plane length 140mm<br>~~es~~|-0.83<br>~~ds~~<br>~~es~~<br>~~de~~<br>~~ss~~|0.88<br>~~ds~~<br>~~es~~<br>~~de Gs~~<br>~~ss~~|1.08<br>~~es~~<br>~~Gs~~<br>~~Gs~~|0.88<br>~~es~~<br>~~Gs~~|1.10<br>~~es~~|0.99<br>~~es~~|
|Ground plane length 130mm<br>~~ee~~|-0.03<br>~~de~~<br>~~ee~~<br>~~ss~~<br>~~ss~~|1.22<br>~~de Gs~~<br>~~ee~~<br>~~ss~~<br>~~ss~~|0.82<br>~~Gs~~<br>~~ee~~<br>~~Gs~~|0.83<br>~~ee~~<br>~~Gs~~|1.14<br>~~ee~~|0.93<br>~~ee~~|
|Ground plane length 120mm<br>~~es~~|-0.64<br>~~ss~~<br>~~es~~<br>~~ss~~<br>~~ss~~|1.09<br>~~ss~~<br>~~es~~<br>~~ss~~<br>~~ss~~|1.17<br>~~Gs~~<br>~~es~~|0.19<br>~~Gs~~<br>~~es~~|0.69<br>~~es~~|0.73<br>~~es~~|
|Ground plane length 110mm<br>~~es~~|-0.89<br>~~ss~~<br>~~es~~<br>~~ss~~<br>~~ss~~|0.55<br>~~ss~~<br>~~es~~<br>~~ss~~<br>~~ss~~|0.31<br>~~es~~|0.10<br>~~es~~|0.79<br>~~es~~|0.92<br>~~es~~|
|Ground plane length 100mm<br>~~es~~|-1.48<br>~~ss~~<br>~~es~~<br>~~ss~~<br>~~ss~~|0.07<br>~~ss~~<br>~~es~~<br>~~ss~~<br>~~ss~~|-0.04<br>~~es~~|-1.48<br>~~es~~|-0.06<br>~~es~~|-0.06<br>~~es~~|
|Ground plane length 90mm<br>~~es~~|-1.64<br>~~ss~~<br>~~es~~<br>~~ss~~|-0.08<br>~~ss~~<br>~~es~~<br>~~ss~~|-0.38<br>~~es~~|-1.85<br>~~es~~<br>~~GO~~|-0.09<br>~~es~~|0.03<br>~~es~~|
|Ground plane length 80mm<br>~~eG~~|-2.65<br>~~ss~~<br>~~eG~~|-1.10<br>~~ss~~<br>~~eG~~<br>~~GO~~|-113<br>~~eG~~<br>~~GO~~|X<br>~~eG~~<br>~~GO~~<br>~~GO~~|X<br>~~eG~~|X<br>~~eG~~|
|Ground plane length 70mm<br>~~ee~~|-3.56<br>~~ee~~<br>~~es~~|-1.82<br>~~ee~~<br>~~GO~~<br>~~es~~|-1.80<br>~~ee~~<br>~~GO~~<br>~~es~~|X<br>~~GO~~<br>~~ee~~<br>~~GO~~<br>~~es~~|X<br>~~ee~~|X<br>~~ee~~|
|Ground plane length 60mm<br>~~es~~|-3.13<br>~~es~~<br>~~es~~<br>~~ee~~|-1.55<br>~~GO~~<br>~~es~~<br>~~es~~<br>~~ee~~|-1.89<br>~~GO~~<br>~~es~~<br>~~es~~<br>~~ee~~|X<br>~~GO~~<br>~~es~~<br>~~es~~<br>~~ee~~|X<br>~~es~~<br>~~ee~~|X<br>~~es~~<br>~~ee~~|
|Ground plane length 50mm<br>~~ae~~|-2.57<br>~~es~~<br>~~ae~~<br>~~ee~~|-1.46<br>~~es~~<br>~~ae~~<br>~~ee~~|-2.04<br>~~es~~<br>~~ae~~<br>~~ee~~|X<br>~~es~~<br>~~ae~~<br>~~ee~~|X<br>~~ae~~<br>~~ee~~|X<br>~~ae~~<br>~~ee~~|



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Updated at June 9, 2026

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