LNA Competition

My ultra low noise amplifier (LNA) was measured yesterday.
Because the LNA was operated at 2.4 GHz ISM band, it had to be measured in our chamber to avoid other interference especially WiFi equipment.

The measured noise figure was below 0.75 dB. However, the small-signal gain is not enough to catch the Spec. And a serious problem is that the LNA is not always stable.
It means that I have a lot of works to do. I want to re-design a whole new one on FR-4 substrate.
I really enjoy doing my researches and my works.
I can't just leave my toys down. XD



* The Truth: NF = 0.62 dB, Gain : 14.05 dB




I need more time. I need more confidence.
I need work hard. I need study hard.


If I have enough time ........
If I spend less time surfing ......



I think I have a conclusion in this dark midnight.

某A

某 A 公司的故事

　　敝實驗室有一台高級的儀器，在去年聖誕節的時候罷工，於是我們送到原廠維修，原廠回覆了故障原因，順便附上維修報價單。

　　維修報價單第一次是90k，過沒多久可能發現90k太少，於是再發一次報價單是120k，這不是私人小公司才會做這種事情嗎？那種"大"公司有蓋章的報價單也有這種事情喔？當然經過我們反應過，還是依照90k的價格。

　　修了三個月，上星期五回來，昨天開啟來測試一下，結果居然是...存在一樣的問題，一樣的問題，一樣的問題！

　　我們等了三個月，付了九萬塊，這像話嗎？


阿你們『不爽不要買，不爽不要修，不爽不要用』阿



這代表幾件事情：
. 維修價格是隨便他們開的，公司想多買一點影料就多開一些，毫無制度。
. 某A公司根本沒搞清楚什麼東西壞掉，於是 "可能" 換掉原本 "好的" 部位。
. 我們錢付太少，A公司只願意修理一半。


希望某公司不要派律師來告我在網路上散播謠言，不過我說的都是事實，都還有單據、日期、照片存證勒。

我也沒說某A公司是哪一間就是~~~

這台儀器掛了，很多碩二的會沒辦法畢業，量LNA NF，量 VCO，量 Mixer...

How to measure a power amplifier

How to measure a power amplifier(PA) ? 

Here are two photos about how to measure the noise figure and gain roughly.

I used a Agilent E4448A PSA and a PA to do the noise calibration.

You can see two PAs on the same plane. The set-up is very fun because the DUT is another PA. Which one is the DUT??  guess ~ 

It is very difficult to measure the linearity (P1dB) especially high power type.

In my lab, we don't have such high power source.