Precautions in PCB design of GSM antenna and Bluetooth antenna

1、 What should be paid attention to in the design of GSM antenna PCB?

Antenna module is an indispensable module for almost all communication electronic equipment. A good antenna design scheme can not only make the equipment run more stable, but also one of the important forms of equipment quality.

Although the antenna design seems to be a small part, it is not easy to ensure the stability of the signal. For the problem that the RF signal of the antenna design is not ideal, here are some information to share with you.

Of course, the antenna design of different modules is also different. Some need to reserve T-type or π type matching circuit for antenna debugging, while others do not need it, which depends on the module.

1. The wiring width of GSM antenna, and the recommended wiring width of two-layer board is 30mil

2. Shielding rules for antenna wiring: take two-layer board as an example. For the bottom layer, the antenna wiring requires that the lower layer needs to be paved, and there shall be no other wiring passing through or parallel; On the top floor, both sides of the antenna wiring are required to be surrounded by a wide area of ground wire, and the distance between the antenna wiring and the ground is greater than 30mil.

3. The antenna routing shape is regular. It is recommended to be short and straight. It is not recommended to change the layer through perforation, right angle routing and antenna length exceeding 3cm.

Antenna module is an indispensable module for almost all communication electronic equipment. A good GSM antenna design scheme can not only make the equipment run more stable, but also one of the important forms of equipment quality.

2、 What should we pay attention to in Bluetooth antenna design?

As mentioned above, what should be paid attention to in the design of GSM antenna PCB? What should be paid attention to in the design of Bluetooth antenna? I hope it can provide help to antenna lovers.

1. Specific PCB routing requirements for board level Bluetooth antenna

The routing is directly from the pad pin. The Bluetooth antenna routing is recommended to be on the same plane of the module (assuming top). The routing width is 15mil, and the distance from the ground on both sides is 15mil. The routing part is required to be short, and the bottom surface needs to be referenced with ground;

2. Recommended Bluetooth antenna

Ceramic antenna, planar inverted F antenna, rod antenna (dedicated to 2.4G frequency), etc. if space allows, try not to choose an antenna with too small size;

3. The Bluetooth antenna should be placed in the corner. If the patch antenna is selected, there should be a clearance area of at least 2mm, and the clearance area should not be far from the ground or other metal parts;

4. It is better to have a large clearance area between the antenna and nearby objects; Otherwise, the matching and adjustment of Bluetooth antenna will become difficult, and the radiation pattern will be seriously distorted;

5. The lower part of the antenna shall not contact the ground and ground plane;

6. The antenna should be placed away from metal objects, such as batteries, chips and other metal objects with overlap.

7. Note that the internal cable (such as battery power line) is too close to the antenna;

8. Monopole antenna needs a reasonable ground to play the best effect.

9. There shall be no metal shell or plastic with metal around the Bluetooth antenna.

10. Do not use very thin antenna feeder, and the width limit shall not be less than 0.1mm.