Tags » CTIA

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

Weekly output: vacation mode for phones, whither unlimited-data plans

The next few weeks will involve a lot of airplanes, starting tomorrow when I fly to Berlin for my fourth annual trip to the IFA electronics show… 261 more words

Weekly Output