Solutions
Home Solutions

How to Test the values of Q on Resonator oscillator & Quartz Crystal

Hot Products

  • 3.2 x 1.5mm SMD Tuning Fork Crystal

    SMD Tuning Fork Crystal PSX315 Features 3215 Size Miniature And Fork Crystal Resonator With A Low Profile Pf 0.75mm. A Ceramic Package Providing High Precision And Reliability. Metal Lid Connected To GND Terminal To Reduce EMI. Noise Resistance Application (Smart Meter Etc.) series resistance 50KΩ max available. AEC-Q200 Compliant Applications Mobile Communications, PDA, Wave Clock, Digital Appliance Auto Motive Applications Such As Multimedia Device More

  • 6.9x1.4mm SMD Tuning Fork Crystal

    SMD Tuning Fork Crystal PMX145 Features Ultra Miniature SMD Tuning Fork Crystal Resonator Plastic molded SMD tuning fork crystal of heat-resistance Metal Lid Connected To GND Terminal To Reduce EMI Suitable For Mobile Communications And Consumer Devices. Applications Mobile Communications And Consumer Devices, Etc. Smart Card And Wearable Devices More

  • 8.0x3.2mm SMD Tuning Fork Crystal

    SMD Tuning Fork Crystal PMX206 Features Ultra Miniature SMD Tuning Fork Crystal Resonator Plastic molded SMD tuning fork crystal of heat-resistance Metal Lid Connected To GND Terminal To Reduce EMI Suitable For Mobile Communications And Consumer Devices. Applications Mobile Communications And Consumer Devices, Etc. Smart Card And Wearable Devices More

  • 9.6x4.0mm SMD Tuning Fork Crystal

    SMD Tuning Fork Crystal PMX405 Features Ultra Miniature SMD Tuning Fork Crystal Resonator Plastic molded SMD tuning fork crystal of heat-resistance Metal Lid Connected To GND Terminal To Reduce EMI Suitable For Mobile Communications And Consumer Devices. Applications Mobile Communications And Consumer Devices, Etc. Smart Card And Wearable Devices More

  • 2.0x6.0mm SMD Tuning Fork Crystal

    SMD Tuning Fork Crystal PMX206F Features Ultra Miniature SMD Tuning Fork Crystal Resonator SMD tuning fork crystal of lead formed heat-resistance Metal Lid Connected To GND Terminal To Reduce EMI Suitable For Mobile Communications And Consumer Devices. Applications Mobile Communications And Consumer Devices, Etc. Smart Card And Wearable Devices More

  • 2.0x6.0mm SMD Tuning Fork Crystal

    SMD Tuning Fork Crystal PMX206FA Features Ultra Miniature SMD Tuning Fork Crystal Resonator SMD Tuning Fork Crystal Of Lead Formed Heat-Resistance Metal Lid Connected To GND Terminal To Reduce EMI Suitable For Mobile Communications And Consumer Devices. Applications Mobile Communications And Consumer Devices, Etc. Smart Card And Wearable Devices More

  • 2.0x6.0mm DIP Tuning Fork Crystal

    DIP Tuning Fork Crystal DT206 Features: A Cylindrical Type Tuning Fork Crystal Resonator Low Power Consuming Tuning Fork Crystal Resonators Are Suitable Not Only For Wristwatches But Also For A Wide Range Of Other Applications From Industrial Equipment To Other The Clock Functions In Consumer And Household Electronics. Applications: Mobile Communications And Consumer Devices, Etc. Smart Card And Wearable Devices More

  • 1.6 x 1.2 x 0.4mm SMD Quartz Crystal

    SMD Quartz Crystal P1SB Features 1612 size ultra miniature and lightweight SMD crystal resonator with a low profile of 0.35mm High precision and high reliability (Frequency aging specification of ±1x10 -6/1 year or ±3x10-6 / 5 year are available for cell phone or wireless communications systems etc. ) Allowing for high density surface mounting. Applications Small mobile devices for next generation like mobile communications short-range wireless modules, digital AV equipment and PC. Wearable devices More

How to Test the values of Q on Resonator oscillator & Quartz Crystal

  • Dec 29, 2020

Values of Q test and the relationship between Qo & the size of cavities


For the cavity filter used in the field of modern mobile communication base stations, the insertion loss is one of the essential RF key indicators. We often expect the smaller the loss, the better: if the insertion loss of the filter can be effectively reduced, it will be of great benefit to the realization of other indicators of the filter or to the entire mobile base station system. The development of modern mobile communications, especially 5G micro base stations, requires the size of filters to become smaller and smaller, which will inevitably bring about the reduction of the unloaded Q value of a single cavity. Therefore, how to effectively use the limited cavity volume and allocate the Q value has become the key to the filter insertion loss.



The designers of most filter design companies design a single cavity with almost the same size for each channel. In fact, the reasonable layout of the size of each single cavity can reduce the insertion loss of the filter, increase the insertion loss margin of the product, and even make the product of the customer index that cannot be achieved in the first place, thereby meeting customer requirements.




1. The relationship between Q value and single cavity size

The Q value is a measure of the average energy storage and loss of the resonant tank. Large energy storage and small loss means high Q value.

The Q value is related to the volume and surface area of a single cavity. The larger the volume, the greater the electromagnetic energy stored in the single cavity. The smaller the surface area, the smaller the loss of the single cavity, and the greater the Q value, and vice versa.

Here we share some reference values of filter single cavity (including circular cavity and square cavity) of different sizes and corresponding Q values of each frequency band. For your reference and reference when designing.


AMPS AMPS
GSM GSM
Cavity size(mm)

F0(RX)

836MHz

Q0

F0(TX)

881MHz

Q0

F0(RX)

902MHz

Q0

F0(TX)

948MHz

Q0

F0

1530MHz

Q0

20 1280
1310
1330
1360
1730
25 1600
1640
1660
1700
2160
30 1910
1970
1990
2040
9590
35 2230
2306
2330
2360
3020
40 2550
2630
2660
2720
3450
45 2870
2950
2990
3060
3880
50 3190
3280
3300
3400
4310
55 3500
3610
3650
3740 4740


DCS DCS PCS PCS UMTS
Cavity size(mm)

F0(RX)

1747MHz

Q0


F0(TX)

1842MHz

Q0


F0(RX)

1880MHz

Q0


F0(TX)

1960MHz

Q0


F0

2140MHz

Q0


20 1850
1900 1920
1960
2040
25 2310
2370
2390
2440
2550
30 2770 2840 2870
2930
3060
35 3230
3310 3350
3420
3570
40 3690
3780 3820
3900
4070
45 4140
4250 4200
4380
4580
50 4600 4720 4770
4870
5080
55 5050 5190 5240
5350
5580


AMPS
AMPS
GSM
GSM

Square cavity size(mm)

F0(RX)

836MHz

Q0

F0(TX)

881MHz

Q0

F0(RX)

902MHz

Q0

F0(TX)

948MHz

Q0

F0

1530MHz

Q0

20×20 1530 1580 1600 1640 2080
25×25
1910 1970 2000 2040 2600
30×30
2300 2360 2390 2450 3110
35×35
2680 2760 2790 2860 3630
40×40
3060 3150 3190 3270 4140
45×45
3440 3540 3590 3600 4660
50×50
3820 3940 3990 4080 5170
55×55
4200 4330 4380 4490 5680


DCS
DCS
PCS
PCS
UMTS
Square cavity size(mm)

F0(RX)

1747MHz

Q0

F0(TX)

1842MHz

Q0

F0(RX)

1880MHz

Q0

F0(TX)

1960MHz

Q0

F0

2140MHz

Q0

20×20
2220 2280 2300 2350 2450
25×25
2770 2850 2870 2930 3060
30×30
3320 3410 3450 3520 3670
35×35
3870 3980 4020 4100 4280
40×40
4420 4540 4590 4680 4890
45×45
4970 5100 5150 5260 5490
50×50
5520 5600 5720 5840 6090
55×55
6070 6220 6290 6420 6700

2. Single cavity Q value test

The performance of the filter resonant circuit is described by the quality factor Q. Various characteristics such as frequency selectivity, bandwidth and damping factor can be derived from it. Its definition is as follows:

value of Q=W (energy storage in average time/energy consumption per second)




Article source WeChat public account: filter


We actually test the Q value of a single cavity:

1. In addition to the resonance frequency to be tested, there can be no other frequency components

2. Don't set the instrument bandwidth too large during testing

3. The external coupling cannot be too large or too small, otherwise the true Q value cannot be measured

So how much external coupling is needed?


When Qe= Qu, Qu= 2QL

QL = f0 / △f3dB

Qu = 0 / △f3dB

Today we shared the "Q value test and the relationship between Qo and single cavity size" through a picture of a physical test case. Hope to help engineers again.


Zhe Jiang A-Crystal electronic technology Co.,Ltd

A-Crystal factory tour: https://www.youtube.com/watch?v=uMqJq6e_8Ew

Web: https://www.acrystals.com/

Email: eva.wang@acrystals.com
Wechat:13857686588

Address: 17th Building, A District, Feiyue Technology Innovation Park, Jiaojiang, Taizhou, Zhejiang, China. ZIP:318014


#32.768kHz Crystal
#32.768khz crystal
#32.768khz
#32.768khz tuning fork crystal
#SMD 3215 32768Hz Xtal
#Electronic Component 32.768KHz
#32.768 khz Crystal Oscillator
#Crystal 32.768 khz
#watch Crystal 32.768 khz
#Quartz Resonator 32.768 KHz
#Resonator 32.768 KHz
#Quartz 32.768 KHz
#32.768KHz DIP Tuning Fork
#12.5pf 20ppm 32.768KHz
#Electronic Component Crystals 32.768KHz
#32.768KHz 6pF Quartz Crystal
#DIP Tuning Fork Xtal 32.768KHz
#Components Resonator 32.768KHz 6pF Quartz Crystal
#32.768KHz Crystal
#32.768KHz Crystal Oscillator
#SMD 32.768KHz
#32.768KHz Crystal 3225
#Oscillator 32.768KHz
#SMD Oscillator 32.768KHz



Copyright © 2015-2021 ZHEJIANG A-CRYSTAL ELECTRONIC TECHNOLOGY CO.,LTD..All Rights Reserved. 浙ICP备18026653号-1

top

Leave a message

Leave a message

    If you have any problem when using the website or our products, please write down your comments or suggestions, we will answer your questions as soon as possible!Thank you for your attention!