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CTIA claims that current wireless privacy rules are fantastic, ignores reality

CTIA is the wireless industry’s top lobbying organization. Their members include AT&T, Verizon and most other major wireless players in the United States. Essentially, whenever the wireless providers want something done without looking like the bad guys, they send CTIA lobbyists in to make the absurd arguments for them. 521 more words

Verizon

AT&T, Verizon Tell FCC That They Should Be Able To Block Texts When They Want To, For Your Own Good

Texting isn’t just the purview of teenagers. Bulk texting is a huge business. Sometimes they’re scam spam in about the same category of usefulness as emails from a wealthy Nigerian prince who doesn’t exist, granted, but sometimes they’re useful blasts from businesses or public entities that let a whole bunch of people get useful information quickly in a low-bandwidth way. 548 more words

LTE MIMO Antennas Analysis

即將進入無線通訊5G的時代,為了提升傳輸速率,手機LTE也開始建立MIMO的技術,新版的CTIA已經將MIMO的測試納入規範,尤其是要賣到日本電信龍頭Docomo的手機,已經要求要測試MIMO的性能。
MIMO的測試,CTIA有定義MIMO的天線治具,這邊挑了LTE Band-13的頻帶,去將模擬及實測量測的結果,一窺有關MIMO的測試及特性。

B-13 Reference Antennas from CTIA
下圖是整理在Band-13的MIMO的天線治具,採用雙天線達到MIMO效果,CTIA定義了Band-13有三大類MIMO天線。

好的MIMO天線要符合
1.低相關係數,要小於0.1
2.高輻射效率,要大於90%
3.低增益差值,也就是兩隻天線的輻射增益的差值,要小於0dB

一般的MIMO天線要符合
1.普通的相關係數,小於0.5
2.普通的輻射效率,大於50%即可
3.低增益差值,也就是兩隻天線的輻射增益的差值,要小於0dB

差的MIMO天線要符合
1.低的相關係數,大於0.9即可
2.低的輻射效率,小於50%即可
3.低增益差值,也就是兩隻天線的輻射增益的差值,要小於0dB

Reference Antenna Simulation Setting… 95 more words

Antenna

Antenna Base Training Antenna Pattern Part

在入門天線工程師之前,必須先懂天線場型怎麼去看,這個是很重要的部分,下面就開始介紹怎麼看天線場型的基本理論,及實際案例。

What is Antenna Gain?
什麼是天線增益,下圖為天線場型的剖面圖,最圓的場型為全向性天線場型,接下來在外圈一點為耦極天線場型,這兩個為天線的基底場型,為什麼叫基底場型,因為天線場型在定義增益時,常用的就是這兩個天線場型作為基底。
1. 絕對增益Gi (dBi):這是最常用的天線增益,如果沒有特別定義的話,一般天線報告都會用這個增益單位,它的基底是全向性天線,全向性天線在真實世界是做不出來的,稱為絕對增益,絕對增益就是與全向性天線的場型來比較。
2. 相對增益Gd(dBd):此天線增益的基底是標準耦極天線的場型,與它做相對的值,它與絕對增益相差2.15dB。


Ref. RF Lab. Of Jinwen University of Science and Technology

Antenna Polarization Define
接下來介紹天線極化的定義,下圖為CTIA Test Plan擷取下來的,這是一個球座標,球座標的定義可以在電磁學的後面章節可以查閱的到,這裡就簡單的介紹用的到的地方。 157 more words

Antenna

Weekly output: UHD + HDR, Apple TV, Apple news, iPhone Upgrade Program, Nextbit Robin

PORTLAND–I’ve just spent two mind- and heart-expanding days at the XOXO festival here. I don’t know if it was quite as inspirational as two years ago… 345 more words

Weekly Output

CTIA ROI: Did I need to go Vegas for this?

LAS VEGAS–My stay here only ran about 38 hours, but even if my itinerary hadn’t gotten upended by flight delays Tuesday I would have only spent 42 hours here. 477 more words

Work

Come Meet Us at CTIA!

We’re just under a week away from CTIA and are so excited to see all of you! Swing by booths 169, 170, and 171 to meet our team! 30 more words