The choice of a microwave capacitor is not always obvious, since requires a detailed comparison. An error in this matter can lead either to an unjustified rise in the cost of the device, or to its insufficient reliability. In this article, a comparative analysis of several parameters of multilayer microwave capacitors of two well-known brands is carried out: ATC and Johanson Technology, and general recommendations are given for choosing between them.
1. General characteristics
Parameter |
|
|
Capacitance range, pF |
0.1 - 27 |
0.1 - 33 |
Working voltage, V |
200 |
50, 200 and 250 |
Temperature range |
-55 ... + 125 deg. FROM |
-55 ... + 150 ° |
MTBF |
2000 h @ + 125 ° C and 2x WVDC |
1000 h @ + 125 ° C and 2x WVDC |
TCS |
0 ... +/- 30 ppm |
0 ... +/- 30 ppm |
Quality factor |
> 2000 @ 1 MHz |
> 10000 @ 1 MHz |
Aging |
not |
not |
Piezo effect |
not |
not |
Moisture resistance |
85 ° C, 85% RH, at rated WVDC, 1000 hours |
40 ° C, 85% RH, 1.5 WVDC, 240 hours |
ATC capacitors meet or exceed EIA-198, MIL-PRF-55681, MIL-PRF-123 standards.
Johanson Technology provides a more flexible choice in terms of operating voltage range. At 50 V, capacitors are available 30, 33 pF, which are not in the ATC line. The rest of the capacitors are available in two versions: 50 and 200/250 V
2. Deviations from nominal capacity
The code |
A |
B |
C |
D |
F |
G |
J |
K |
M |
ATC, Deviation, +/- |
0.05 pF |
0.1 pF |
0.25 pF |
0.5 pF |
one % |
2% |
five % |
ten % |
20 % |
Johanson, Deviation, +/- |
0.05 pF |
0.1 pF |
0.25 pF |
0.5 pF |
one % |
2% |
five % |
ten % |
|
3. (ESR)
. 1 ESR ATC
. 2 ESR Johanson Technology
1 ESR ATC 0.07-0.09 , Johanson Technology 0.07-0.1 , .. .
2 ESR ATC 0.12-0.14 , Johanson Technology 0.14-0.18 . .. ATC ESR 15-30% .
, . <1 ESR .
4.
. 3 Johanson Technology
ATC . , >2000 @ 1 .
5. (SRF)
. 4 SRF ATC
. 5 SRF Johanson Technology
, ATC : 12 @ 1 9 @ 1 4 3- 10 .
, , . ATC RO4350 10 mil ; Johanson Technology RO4003 16 mil.
6.
. 6 Johanson Technology
Similar data for ATC capacitors is not given.
Thus, ATC capacitors have higher reliability and better ESR above 2 GHz. At frequencies below 1 GHz, Johanson Technology capacitors are not inferior to them in terms of parameters and are significantly cheaper. This is essential for such mainstream applications as the IoT.