射頻功率計(jì)APM-16性能特點(diǎn)
美國(guó)鳥(niǎo)牌BRID 射頻功率計(jì)APM-16
范圍:2MHz-2.3GHz、1W-1000W
Average-Reading Portable Wattmeter Designed especially for RF power measurement in PCS, cellular, ESMR, paging similar communication systems Equally effective for measuring RF power in conventional analog systems Uses APM-series plug-in elements to cover a wide range of frequency power levels. Simple Thruline® style operation for instant forward or reflected power readings Interchangeable QC connectors for fast
美國(guó)鳥(niǎo)牌BRID 射頻功率計(jì)APM-16
The Model APM-16 RF wattmeter is designed to keep pace with theever growing complexity of digitally-based communication systems.Birds Model 43 most other wattcmeters available today weredesigned to measure power of constant amplitude, sinusoidalwaveforms. Modern wireless communication systems can use a varietyof digital techniques to combine many voice data channels into acomplex, composite RF signal. Measurement of such signals with aconventional wattmeter may yield unacceptable errors. The APM-16employs active circuitry to deliver accuracy of ± 5% formultiple-access technologies such as CDMA, TDMA, FDMA otherdigitally-encoded communication systems.
Accuracy: |
10° to 35° C ±4% reading, ±1% full scale,–20° to 50° C ±6% reading, ±2% full scale |
Battery: |
Internal 9 volt |
Connector: |
QC type (Female N normallysupplied) |
Frequency Range: |
2 MHz to 2.3 GHz |
Huity: |
95% ±5% max. (noncondensing) |
Insertion VSWR: |
(with N connector) 1.05 max. to 1000MHz |
Meter: |
Shock mounted, linear scale with expedscales of 25, 50 100 for full scale 1 to 1000 W readings.Mirrored scale includes 5% overrange. |
Nominal Size: |
6 7/8" H x 5 1/8" W x 3 5/8" D, (175 mm x130 mm x 92 mm) |
Peak/Average Ratio: |
In excess of 10 dB |
Power Range: |
1 W to 1000 W |
Setting Time: |
< 1 second |
Temperature Range: |
–20° to 50° C operating; –25° to 65° Cstorage |
Weight: |
3 lbs. (1.4 kg) |
APM-16射頻功率表|射頻功率計(jì)探頭選型表
APM-16 Elements - 7/8" LineSection |
|
FrequencyBs (MHz) |
PowerRange |
2-30 |
25-60 |
50-125 |
100-250 |
200-500 |
400-1000 |
950-1260 |
1100-1800 |
1700-1990 |
1990-2200 |
2000-2300 |
1W |
- |
- |
APM-1B |
APM-1C |
- |
APM-1E |
APM-1J |
- |
APM-1L1 |
APM-1L2 |
APM-1M |
2.5W |
- |
- |
APM-2.5B |
- |
APM--2.5D |
APM-2.5E |
APM-2.5J |
APM-2.5K |
APM-2.5L1 |
APM-2.5L2 |
- |
5W |
APM-5H |
APM-5A |
APM-5B |
APM-5C |
APM-5D |
APM-5E |
APM-5J |
APM-5K |
APM-5L1 |
APM-5L2 |
- |
10W |
APM-10H |
APM-10A |
APM-10B |
APM-10C |
APM-10D |
APM-10E |
APM-10J |
APM-10K |
APM-10L1 |
APM-10L2 |
- |
25W |
- |
- |
APM-25B |
APM-25C |
APM-25D |
APM-25E |
- |
APM-25K |
APM-25L1 |
APM-25L2 |
- |
50W |
- |
- |
- |
APM-50C |
APM-50D |
APM-50E |
APM-50J |
APM-50K |
APM-50L1 |
APM-50L2 |
- |
100W |
APM-100H |
APM-100A |
APM-100B |
APM-100C |
APM-100D |
APM-100E |
APM-100J |
- |
APM-100L1 |
- |
- |
250W |
APM-250H |
APM-250A |
APM-250B |
APM-250C |
APM-250D |
APM-250E |
- |
- |
- |
- |
- |
500W |
APM-500H |
_ |
APM-500B |
APM-500C |
APM-500D |
APM-500E |
- |
- |
- |
- |
- |
1000W |
APM-1000H |
_ |
APM-1000B |
APM-1000C |
_ |
APM-1000E |
- |
- |
- |
- |
- |
如何使用駐波比表 BV3FG 若以功率的觀點(diǎn)來(lái)看 駐波比可以表示為: SWR = (√Po + √Pr)/(√Po - √Pr) Po:進(jìn)入天線系統(tǒng)的功率 Pr:從天線系統(tǒng)反射回來(lái)的功率 經(jīng)過(guò)運(yùn)算 SWR 與 Pr/Po (反射功率百分比)的關(guān)系如下: Pr/Po = [(SWR-1)/(SWR+1)]^2 駐波比表基本上就是功率表。它可以量測(cè)輸入功率及反射功率。但根據(jù)上式,不管輸入功率為何,反射功率一定和輸入功率成一定的比例。也就是說(shuō),對(duì)同一駐波比,不管輸入功率為何,只要是在量輸入功率時(shí)利用可變電阻調(diào)整驅(qū)動(dòng)表頭的電流使指針達(dá)到滿刻度。那麼你量測(cè)反射功率時(shí),指針一定是指在同一個(gè)位置。把這些相關(guān)位置標(biāo)出來(lái),我們的功率表上就多了一排刻度,叫做"駐波比",而您的功率表馬上搖身一變成為"駐波比表"了。
說(shuō)穿了,駐波比表就是功率表。在量測(cè)功率時(shí)它預(yù)設(shè)了幾組功率(如5W,20W,200W)使輸入功率恰好是這個(gè)位準(zhǔn)時(shí)(5W, 20W,200W),指針會(huì)達(dá)到滿刻度。當(dāng)你撥在CAL位置時(shí)就是量輸入功率,只不過(guò)你可以調(diào)整指針位置。當(dāng)你撥在SWR位置時(shí)就是量反射功率,只不過(guò)您這時(shí)候看的是SWR的刻度。
以DIAMOND系列的駐波比表而言,它有一個(gè) Calibration 旋鈕及三個(gè)選擇開(kāi)關(guān):PowerRange,F(xiàn)unc,F(xiàn)WD/REF SWITCH。用法如下。
量輸入功率:
1.將 POWER RANGE 撥到200W,F(xiàn)UNC 撥到PWR,F(xiàn)WD/REF 撥到FWD; 2.按下無(wú)線電機(jī)的發(fā)射鍵; 3.適度選擇 POWER RANGE 以精確讀出功率。
量反射功率:
1.將 POWER RANGE 撥到200W, FUNC 撥到PWR, FWD/REF 撥到REF; 2.按下無(wú)線電機(jī)的發(fā)射鍵; 3.適度選擇 POWER RANGE 以精確讀出功率。
量駐波比:
1.將 FUNC 撥到CAL 位置,CALIBRATION 旋鈕反時(shí)針?lè)较蛐D(zhuǎn)到底; 2.按下無(wú)線電機(jī)的發(fā)射鍵,調(diào)整 CALIBRATION旋鈕使指針達(dá)到滿刻度; 3.將 FUNC 撥到 SWR 位置,由表頭的 SWR 刻度讀出駐波比的讀值。
使用駐波比表量測(cè)天線的駐波比時(shí)要盡量將駐波比表靠近天線端,因?yàn)閭鬏斁的傳輸損耗會(huì)使得所量出來(lái)的駐波比數(shù)值較小,變成"快樂(lè)駐波比"。例如,原本天線的駐波比為 1.92 (反射功率百分比為10%),現(xiàn)在加上一段 cable 衰減量為3dB,假設(shè)無(wú)線電機(jī)的發(fā)射功率為10W,則經(jīng)由 CABLE 傳到天線的輸入端時(shí)只剩下5W,然後反射10% 即 0.5W,0.5W經(jīng)由傳輸線送回來(lái)只剩下0.25W,所以駐波比量到的是輸入 10W,反射 0.25W,反射功率百分比為 2.5%,即 SWR=1.03量起來(lái)真是快樂(lè)的不得了。
此外,目前大部份的駐波比表都是利用感應(yīng)的方式將信號(hào)感應(yīng)到駐波比表內(nèi)的量測(cè)電路,所以在量測(cè)時(shí)可以一邊發(fā)射一邊切換駐波比表上的開(kāi)關(guān),這并不會(huì)損壞無(wú)線電機(jī)。如果小心一點(diǎn),不要讓指針?biāo)查g打到底。駐波比表要壞掉也蠻難的。
最後提醒一點(diǎn),天線的好壞不能單看駐波比,F(xiàn)在大家如此迷信駐波比的原因很簡(jiǎn)單,因?yàn)轳v波比表到處都買得到。我的意思是說(shuō),不要因?yàn)樘炀駐波比很低就覺(jué)得一切OK而沾沾自喜,多研究天線的其它特性才是真正的樂(lè)趣.
美國(guó)鳥(niǎo)牌(Bird)射頻功率計(jì)(RF功率表)選型一覽
功率計(jì)型號(hào) |
43 |
4304A |
4391A |
4410 |
APM16 |
4305 |
4431 |
4314B |
4308 |
5000/5010 |
頻率段(MHz) |
功率段 |
|
2-30 |
50W-10KW |
√ |
√ |
√ |
√ |
√ |
√ |
√ |
√ |
|
√ |
25-60 |
50W-1KW |
√ |
√ |
√ |
√ |
√ |
|
√ |
√ |
|
√ |
50-125 |
25W-1KW |
√ |
√ |
√ |
√ |
√ |
|
√ |
√ |
|
√ |
100-250 |
25W-1KW |
√ |
√ |
√ |
√ |
√ |
|
√ |
√ |
|
√ |
200-500 |
25W-500W |
√ |
√ |
√ |
√ |
√ |
|
√ |
√ |
√ |
√ |
400-960 |
10W-500W |
√ |
√ |
√ |
√ |
√ |
|
√ |
√ |
|
√ |
950-1260 |
5W-250W |
√ |
|
√ |
√ |
√ |
|
√ |
√ |
|
√ |
1100-1800 |
1W-50W |
√ |
|
√ |
√ |
√ |
|
√ |
√ |
|
√ |
1700-1990 |
1W-50W |
|
|
|
|
√ |
|
|
|
|
√ |
1990-2200 |
1W-50W |
|
|
|
|
√ |
|
|
|
√ |
√ |
2200-2300 |
1W-25W |
|
|
|
|
√ |
|
|
|
|
√ |
2400-2500 |
1W-25W |
|
|
|
|
√ |
|
|
|
|
√ |
2600-2700 |
1W-25W |
|
|
|
|
√ |
|
|
|
|
√ |
3400-3500 |
1W-10W |
|
|
|
|
√ |
|
|
|
|
√ |
3500-3600 |
1W-10W |
|
|
|
|
√ |
|
|
|
|
√ |
|