Radiation Interference Solution (Radisol)

The Radiation Interference Solution (Radisol) is a device that suppresses interference between antennas in close proximity to each other to improve the antenna characteristics.
When two or more antennas with similar communication bands are placed in close proximity to each other, interference between the antennas becomes more likely to occur. Some of the antenna characteristics may then deteriorate. It is possible to suppress this interference and improve the antenna radiation efficiency at such times by mounting a Radisol to the matching circuit part of the antenna that is interfering with the other antennas.

萝莉影视overview
萝莉影视Lineup
Datasheet
Example applications
Inquiries

萝莉影视overview

The Radisol is a device that has the function of suppressing interference between antennas in close proximity to each other.
Fig. 1 shows an example of the equivalent circuit of the Radisol. We produce magnetic coupling by placing the two coils of L1 and L2 in close proximity to each other with our unique multilayer technology. In addition, this forms a structure that generates mutual inductance between the short paths. This mutual inductance and L2 and C1 form a parallel resonant circuit, which suppresses unnecessary power inflow and interference to improve the antenna characteristics.

This device is a two-terminal ultra-small chip component with a size of 0603 mm (Fig. 2).
It is possible to use the mounting land of the existing matching circuit as it is without affecting the matching characteristics by also adding improvements in the circuit to suppress the inductance value of the path through the band. Moreover, the Radisol makes it possible to take a measure against interference with one element in comparison to a measure against interference using a parallel resonant circuit consisting of the two elements of L and C. Therefore, the mounting area can be reduced by approximately 62% compared to the two-element measure against interference.

Fig. 1: Example of the equivalent circuit

Fig. 2: Photograph of the exterior

The figure below shows an image of how the Radisol operates.
If the antenna characteristics deteriorate due to interference from antennas with similar communication bands, mounting a Radisol to antenna B, which receives the power inflow, will make interference between the antennas less likely to occur. In addition, the Radisol's insertion loss is small. This means it does not significantly affect the antenna characteristics.

No measure
against interference

Some of the power radiated from antenna A flows into antenna B and interferes with it when antennas A and B are in close proximity to each other.

⇒ The characteristics of antenna A deteriorate

Conventional measure
against interference

A typical measure against interference is to suppress the inflowing power by mounting an LC parallel resonant circuit as a notch filter to antenna B that is interfering with antenna A.
However, when antennas have similar communication bands, there is a concern that the antenna radiation efficiency may deteriorate due to loss in this circuit.

⇒ The characteristics of antenna B deteriorate

Measure against interference
using the Radisol

It is possible to keep the impact of the radiation characteristics on antenna B low even when there is interference between antennas with similar communication bands by using a Radisol in place of an LC parallel resonant circuit.

⇒ Ensures the desired antenna characteristics for both antennas A and B

Radisol's operating principle

L1 and L2 are magnetically coupled. Moreover, mutual impedance (+M) occurs in the short path.

A parallel resonant circuit (blue box) is formed including the mutual inductance of the short path (+M). This mutual inductance acts as an ideal inductor with no loss. Therefore, the parallel resonant circuit forms a high Q notch filter.
In addition, increasing the inductance of L2 (and simultaneously increasing the resistance components as well) makes it possible to suppress fluctuations in the antenna resonance frequency caused by variations in the inductance.

On the other hand, when power is radiated, it does not pass through L2, which has resistance components (some of the insertion loss) and a large impact on the aforementioned antenna resonance frequency.
Therefore only the power radiation is affected by L1. Accordingly, reducing the L1 value makes it possible to keep the insertion loss during power radiation and its impact on the antenna resonance frequency low.

Examples of improving the antenna characteristics

We use an evaluation board to introduce here the effect of improving the radiation characteristics.
Fig. 3 shows an evaluation board with a GPS antenna (1.5 GHz) and Wi-Fi™ (2.4GHz / 5GHz) antenna placed in close proximity to each other.

Fig. 3: GPS antenna part and Wi-Fi antenna part before a Radisol is mounted to it

We mount the Radisol to the Wi-Fi antenna that is affecting the GPS antenna (Fig. 4).

Fig. 4: Matching circuit part of the GPS and Wi-Fi antennas before and after mounting the Radisol

The GPS antenna's efficiency improves as a result of mounting the Radisol (Fig. 5).
Moreover, there is also no impact on the resonance frequency of the Wi-Fi antenna even when mounting the Radisol. Accordingly, no major deterioration is seen in the antenna characteristics.

Fig. 5-1: GPS antenna radiation efficiency before and after mounting the Radisol

Fig. 5-2: Wi-Fi antenna radiation efficiency before and after mounting the Radisol

萝莉影视Lineup

We have a lineup of products tailored to the frequency band in which the measures against interference are taken.

P/N	Improve Band		Pass Band
P/N	Band name	Attenuation f0	IL < −0.5dB (Typ) @50Ω
LXTS03S3G3-001	n78	3.3 GHz	to 2.2 GHz	4.3 to 8.0 GHz
LXTS03S4G4-002	n79	4.4 GHz	to 3.9 GHz	5.1 to 8.0 GHz
LXTS03S1G5-003	GPS L1	1.5 GHz	to 1.0 GHz	2.0 to 5.6 GHz
LXTS03S1G5-004	GPS L1	1.5 GHz	to 0.7 GHz	2.3 to 6.6 GHz
LXTS03S1G5-005	GPS L1	1.5 GHz	to 1.2 GHz	1.8 to 5.8 GHz
LXTS03S1G8-006	Band3	1.8 GHz	to 1.7 GHz	2.1 to 8.0 GHz
LXTS03S5G7-007	Wi-Fi 5G	5.7 GHz	to 4.9 GHz	6.3 to 8.0 GHz
LXTS03S1G2-008	GPS L5	1.2 GHz	to 0.9 GHz	1.4 to 8.0 GHz
LXTS03S1G5-009	GPS L1	1.5 GHz	to 1.4 GHz	1.8 to 7.6 GHz
LXTS03S5G7-010	Wi-Fi 5G	5.7 GHz	to 4.1 GHz	6.6 to 8.0 GHz
LXTS03S2G5-011	HB / Wi-Fi 2G	2.5 GHz	to 2.1 GHz	2.9 to 8.0 GHz

Datasheet

Download datasheet

A datasheet common to the entire series and listing product characteristics, reliability data, packing specifications, etc., is available for download.

Example applications

You can use the Radisol in devices with multiple antennas on a small terminal such as smartphones, smartwatches, and wearables.

Inquiries

Please feel free to contact us via the links below with questions or inquiries regarding samples, estimates, etc.

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