Using the DW3220 chip to measure the distance, the actual distance between the Tag and the Anchor is Rr=1.5m.
The Tag rotates 360 degrees around the Anchor and measures the distance Rd (electronic feedback distance).
Is Rd reliable? The Tag faces away from the antenna (the antenna of the Anchor board). Is the measured distance Rd still within the usable range?
If there is a successful example, can you provide a demo code?
The current antenna is on a copper mold point, exposed on one side of the board, the front. The circuit board is a single-sided board. There is no antenna on the back.
Can the antenna be designed as a three-dimensional exposed point? Will the effect be better?
I can’t upload pictures
@wangqian , I’m not sure I am fully understanding the question but have you looked at our SDK 1.0.2 which can be found in the documents section of the page here? DW3220 - Qorvo
With this SDK, you can use FiRa ranging to do DS-TWR and get the distance on both the tag and anchor.
This implies that the angle on the anchor antenna is changing.
You make no mention of the tag orientation, it could be maintaining a constant heading (meaning the angle to the anchor is changing) or maintaining the same face towards the anchor.
You make no mention of angle of arrival measurement so I’ll ignore that.
You only mention the chip used and make no mention of antenna type or mechanical design. This will have a huge impact on the results.
Is the measured distance Rd still within the usable range?
The answer is that it depends on your physical design and implementation and your definition of usable.
For any reasonable design you will get a range at all points in the circle. If your antenna and all equipment within the antenna near field has rotational symmetry then you will get exactly the same range at all points.
For the vast majority of designs (chip/pcb antenna on a pcb with electronics close by) you will see some variation in range as you rotate around the anchor. This is caused by the gain and the delay within the antenna changing with orientation. How much will depend a huge amount on the design used but typically this effect will be in the order of 10 cm.
For demo code see any of the ranging demo examples.
The current antenna is on a copper mold point, exposed on one side of the board, the front. The circuit board is a single-sided board. There is no antenna on the back.
Can the antenna be designed as a three-dimensional exposed point? Will the effect be better?
I can’t upload pictures
It becomes a question of how good is good enough for your application because even a theoretically perfect design will have some variation in the real world..
3d exposed copper is normally done by soldering a piece of metal to the board and calling it an antenna.
A standard monopole antenna over a ground plane has good rotational symmetry but isn’t good for UWB bandwidths. A conical antenna over a ground plane or a bi-conical antenna in free space would be UWB equivalents, they give a symmetrical pattern over a full 360 degrees (in a plane, you still get variation vertically). However they add a lot of mechanical complexity to the design.